Caramelized Onion, Mushroom, Apple & Gruyere Bites


Caramelized Onion, Mushroom, Apple, and Gruyere Bites are the PERFECT appetizer!

Caramelized Onion, Mushroom, Apple, and Gruyere Bites are the PERFECT appetizer!

Caramelized Onion, Mushroom, Apple, and Gruyere Bites are the PERFECT appetizer!

Caramelized Onion, Mushroom, Apple, and Gruyere Bites are the PERFECT appetizer!

This is a must-have appetizer for Thanksgiving. It looks elegant and at first thought, it probably looked to you like a difficult and time-consuming appetizer to make. Well, like I said last week, for Thanksgiving or any dinner party, I prefer simple elegance. I don’t want to slave away in the kitchen for two hours on one dish. Simple and delicious is my middle name.

While everyone is waiting for the big meal, have everyone snack on these. You should probably make a double batch, too, because I guarantee you they will not last long. The caramelized onions give this appetizer a sweet flavor but when paired with the sautéed mushrooms and tart apple it completes the palette in your mouth. Mixed together with the earthy taste of gruyere cheese – you have yourself a perfect appetizer everyone will love. Since the gruyere cheese is mixed into the onion, mushroom, & apple mixture, it melts beautifully together when baked. It’s bubbly and cheesy goodness.

I loved how the puff pastry acted like a light, buttery pillow for the filling on top. They just paired so well together and the flavors are out of this world. They’re the perfect size for the perfect bite.

As an after-thought, adding chopped up bacon on top of these would make these even more enticing. Next time I make these for guests, I will definitely be adding pieces of bacon on top or pancetta would work well too.

You need these next Thursday.

Caramelized Onion, Mushroom, Apple & Gruyere Bites
Prep Time
10 mins
Cook Time
1 hrs 5 mins
Total Time
1 hrs 15 mins
You must add these caramelized onion, mushroom, apple, & gruyere bites to your Thanksgiving appetizer list.
Servings: 30 -32
  • 2 tbsp vegetable oil
  • 1 large onion, thinly sliced
  • 4 oz baby bella mushrooms, sliced
  • 2 tbsp unsalted butter
  • 1 1/2 granny smith apples, cubed into 1/2-inch cubes
  • 1 tsp granulated sugar
  • 1 1/2 oz grated gruyere cheese
  • 2 tbsp chives, minced
  • 1/2 tsp dried thyme
  • 1: 1 pound package of frozen puff pastry, thawed
  • 1 egg, beaten
  1. Preheat oven to 400 degrees. Line baking sheets with silicone baking mats. Set side.
  2. In a large skillet, heat the vegetable oil and cook the onions (with 1 tsp. of salt) until they're golden brown, about 30 minutes. Remove and set aside in a large bowl. In the same skillet, sauté mushrooms until tender, about 5 minutes. Remove and set aside in the bowl with the onions.
  3. In the same skillet, melt the butter and add in the apples with the sugar. Cook until softened, about 10 minutes. Remove from pan and add to the large bowl with onions and mushrooms.
  4. Add the cheese, chives, and thyme to the bowl and stir to combine the mixture well. Season with salt and pepper, to taste.
  5. With a pizza cutter, cut the puff pastry into 2-inch squares and place them on the lined baking sheets. Using a pastry brush, brush beaten egg on the squares.
  6. Using a tablespoon, place filling in the middle of each puff pastry.
  7. Bake for 25 minutes, rotating the pans halfway through and switching the baking sheet on the top rack to the bottom and the bottom to the top, until the pastry is golden brown and crisp.
  8. Let the tarts cool a bit before serving, you don't want people to burn the roofs of their mouths!
Recipe Notes

Source: Williams-Sonoma



Posted on November 15, 2012

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  1. Michelle
    12/10/2012 at 2:44 pm

    I made these for a party yesterday and they were so delicious! I left the puff pastry to thaw for too long (and couldn’t unroll it), so mine ended up a little more puffy than yours, but it was still delicious! Great flavor combination, so thanks for sharing the recipe!

    • 12/10/2012 at 2:46 pm

      Oh great! I’m glad they worked out for you :) puffy puff pastry isn’t a bad thing! ;) Thanks for coming back to share!

  2. Luisa
    12/19/2012 at 11:27 am

    These look INCREDIBLE!!!!!! Would they be AS good if I used cheddar, or does it taste best with Gruyere? Thanks!!!

    • 12/19/2012 at 11:54 am

      I definitely think gruyere is better because of its unique taste and how it compliments so well with caramelized onions!

    • The Pink Chef of Dallas
      05/02/2016 at 4:30 am

      I also would use brie

  3. Joey Youngstrom
    12/27/2012 at 7:43 pm

    Made these today and OMG! They are so good!!

  4. Jackie
    12/31/2012 at 11:19 pm

    Made these tonight and 3 people asked for the recipe! I made them on baguette slices to save some time. Came out awesome!

  5. 01/04/2013 at 8:17 am

    What kind of onions did you use?

  6. Izabela
    02/24/2013 at 11:34 am

    I made this and I thought it was delicious! Some of the party girls said it was too oniony.

  7. Sue
    03/11/2013 at 1:48 pm

    Help! Got stumped with the phyllo sheets….one to a baking sheet seemed too flimsy. Do you use just one or do you stack a couple? These sound delicious but need help with the phyllo….have always been intimidated by phyllo dough. Thanks.

    • 03/11/2013 at 1:54 pm

      Phyllo dough was not used in this recipe. I used puff pastry sheets, which are two different things that, if used interchangeably, can give different results.

  8. Tina
    04/03/2013 at 9:56 am

    I want to try to make this appetizer for a work snack day this week, but would like to prepare it the night before then bake it at work the next day. Will this work out? Or will all the ingredient be sitting to long on the uncooked dough?

    • 04/03/2013 at 10:59 am

      I would keep the filling and the puff pastry separate otherwise your dough would get way soggy.

  9. Tina
    04/03/2013 at 3:24 pm

    Thanks Julie! That makes sense!

  10. 06/22/2013 at 2:50 pm

    I finally made these last night, and OMG! They turned out fabulously! I made the filling in the morning and kept it in the fridge until dinnertime, assembled them and baked them and wow. Just wow. They were a huge hit at our dinner party, and they’ll definitely be on repeat here :)

  11. Judith
    10/11/2013 at 4:03 pm

    Would it be ok to use parchment paper? I do not have a silicone liner

    • 10/11/2013 at 11:15 pm

      Yup, parchment paper would be ok! :)

  12. 11/08/2013 at 1:50 pm

    Wow these sound so delicious and absolutely perfect for a Thanksgiving spread! Actually any holiday spread really…I might include them in my Chanukah dinner :)

  13. Bev
    11/24/2013 at 3:01 pm

    Definitely adding these to my menu. Do you think it would be okay to make these the day ahead or not? Please advise. Thanks!

    • 11/24/2013 at 3:35 pm

      Hi Bev! So glad you’re adding this to your menu! Makes me happy! As far as your question goes, I advised a lady above that you could make the filling & puff pastry ahead of time but keep the filling and puff pastry separate until you’re ready to assemble & warm them up; otherwise, your puff pastry will just get way too soggy. I hope this helps and I hope everyone enjoys! :)

  14. renita
    12/13/2013 at 3:07 pm

    Hi Julie,

    This recipe looks delicious! I was planning to try it out. Do you use apple with skin or without?

    • 12/14/2013 at 6:46 am

      Hi Renita! I used apples with skin. Enjoy!

  15. VZ
    08/06/2014 at 8:01 pm

    Have made these from this site so many times over the last couple of years. This is one of our party favorites – it has sophisticated flavors yet is easy to make. Highly recommended.

    • Julie
      08/06/2014 at 8:26 pm

      Thanks for letting me know! I’m so glad you have made these so many times :)

  16. 08/29/2014 at 8:03 am

    Julie, I have puff pastry in my freezer!! Going to try this recipe! love it!

  17. Misty
    09/13/2014 at 11:27 am

    These look delicious! I want to make them for a Wine Pairing dinner I’m going to at a friends house. And I was wondering if you had a suggestion of a varietal of wine that would go with these?

    • Julie
      09/14/2014 at 11:44 am

      Hi Misty, I know white wines pair well with the ingredients in this appetizer. My personal favorite is Kim Crawford’s Sauvignon Blanc!

  18. Mary Ann
    10/30/2014 at 7:30 pm

    I made this tonight. Did not change a
    thing. Truly one of my favorites on Pinterest. So awesome.

    • Julie
      10/31/2014 at 7:09 am

      This is one of the most popular :) glad you enjoyed it again!

  19. Barbara
    12/05/2014 at 6:58 pm

    Looking forward to trying this recipe for a party next weekend not sure which pepperidge farm puff pastry to use the sheets then cut into pieces the shells or cups? Thank

    • Julie
      12/06/2014 at 8:35 pm

      I just bought the big sheet and cut them into squares myself.

  20. Deb
    01/31/2015 at 9:48 pm

    When do you add the bacon? Before baking I assume…

    • Julie
      02/01/2015 at 8:59 am

      Yes, I’d add it before baking.

  21. Petra
    02/23/2015 at 5:05 am

    Can you please give me the ingredients needed in GRAMS/ML?

    • Julie
      02/23/2015 at 8:48 am

      Hi Petra, sorry, I’m not familiar with that measurement conversion. You can use Google and there are numerous conversion calculators out there.

  22. Darbi
    03/11/2015 at 7:31 pm

    Hi There what do you think about making them and freezing? Then bake off at the party?

    • Julie
      03/13/2015 at 7:45 am

      I would freeze the topping separately from the puff pastry because you don’t want it to get soggy.

  23. Lea
    05/10/2015 at 11:59 am

    When cooking what are the temperature of the skillet? Low med ?

    • Julie
      05/11/2015 at 6:16 am


  24. Shannon
    05/28/2015 at 12:52 pm

    I would like to make these for a friends baby shower. But the facility does not have an oven (just fridge). What if I bake and keep separate then serve at room temperature. Do you think that would be Okay?

    • Julie
      05/29/2015 at 7:43 am

      Yes, that’s a great idea!

  25. Frances
    06/14/2015 at 2:02 pm

    I made these and added pickled okra and hazelnut to the mix. WOW!! A must try flavor explosion!!

  26. Mary Ann
    09/16/2015 at 12:34 am

    I have made these several times.

  27. Mimi
    10/09/2015 at 8:08 pm

    Would it work if I baked the puff pastry in one sheet, spreading the apple/onion mixture over the whole thing, bake and cut after they’re cooked?

    • Julie
      10/10/2015 at 7:29 am

      It sounds like a great idea! However, I’m not sure if the mixture will be too heavy for the entire sheet of puff pastry to rise and it might be too wet of a mixture to be sitting on the whole puff pastry sheet so it might be soggy. You can certainly try it your way though!

  28. Sophie
    10/19/2015 at 1:20 pm

    Someone mentioned bacon in the comments, is bacon a part of the recipe?

    • Julie
      10/20/2015 at 12:38 pm

      No it isn’t. Probably just something they wanted to add to give it some extra oomph

  29. Wendi
    11/06/2015 at 11:06 am

    These were a hit and very yummy. Easier to do than I thought and everyone loved them.

  30. Layla
    11/17/2015 at 6:18 am

    Can I use any kind of cheese instead of Guerroyere?

    • Julie
      11/18/2015 at 7:22 am

      You can but gruyere compliments the other flavors of this appetizer so well that I highly encourage you to use gruyere!

  31. Denise
    11/19/2015 at 4:24 pm

    Hi I just made these. They came out good, however, I was wondering if the measurement of 1 1/2 oz of Gruyere cheese is correct. Seemed like a small amount and didn’t really taste it in puffs.
    Please advise.
    Thank you

    • Julie
      11/20/2015 at 7:57 am

      It is correct, however, I’m usually generous with cheese so feel free to add more if you like.

  32. jay
    11/23/2015 at 10:12 pm

    want to make these non-dairy…what can i use to substitute for the gruyere…


    • Julie
      11/24/2015 at 9:31 pm

      Maybe use a vegan cheese of your choice?

  33. 11/26/2015 at 7:10 am

    Totally last minute but I’m making these for thanksgiving dinner tonight and wanted to know if it’s okay to serve them at room temperature or reheat them? I have to make them at my house and then drive to my sisters house which is an hour away. I know you commented about them getting soggy so I thought I would leave them uncovered until I get there and then reheat them.

    • Julie
      11/26/2015 at 11:49 am

      You can serve them however you want – room temperature or reheated out of the oven. But yes, they may get a bit soggy with the ingredients sitting on top of the puff pastry.

  34. Debbie
    05/04/2016 at 12:23 pm

    These sound fabulous. One question though. Do you think Gouda would work here? Thanks for a great recipe. I’m planning on making these for my Sister’s Weekend.

    • Julie
      05/05/2016 at 8:39 am

      Yes, gouda should be fine to use.

  35. Lidia
    08/27/2016 at 10:48 am

    What can I use instead of cheese?.

    • Julie
      08/28/2016 at 8:53 am

      Hmm, I’m not quite sure. The gruyere really makes this dish have that distinct taste! Maybe just omit the cheese if you really don’t want it.

  36. Barry
    09/01/2016 at 7:35 am

    Hi Julie, I have just looked over your fabulous recipe. My sister is hosting a high tea for our Mum’s 85th Birthday and I thought that your recipe would be perfect as one of the many things we will make to celebrate her 85th. It is foodies like yourself that make the world such a wonderful place to share recipes and enjoy life’s simple pleasures.

    • Julie
      09/01/2016 at 12:23 pm

      Thanks for such a sweet note, Barry. I hope you all enjoy this recipe and happy birthday to your mum!

  37. Dieselle
    09/02/2016 at 11:31 am

    These look so delicious. Thank you for reposting this recipe.
    I agree, adding a pork product would kick it up a notch. If one adds pieces of bacon on top before baking, is the bacon pre-cooked or are the pieces of bacon uncooked?
    I assume cooked as there would be too much fat from the bacon as it cooks, but if it is cooked, does it not burn or get tough in the oven?

    • Julie
      09/03/2016 at 8:33 am

      I would pre-cook the bacon then sprinkle the bacon on after the bites come out of the oven :)

  38. Darcey
    09/16/2016 at 11:45 pm

    Do you really cook the onions for 30 minutes or is that a misprint?

    • Julie
      09/17/2016 at 8:23 am

      To caramelize onions, you need to cook them for a long time :) it is not a misprint.

  39. Alicia
    10/02/2016 at 1:24 pm

    HELP! Making these right now and just realized I thawed the puff pastry too long. I can’t speed at the sheets at all! Also just realized that it’s not a full pound which means I’ll need to buy more but I don’t think it will thaw in time! What do I do???

    • Julie
      10/03/2016 at 8:57 am

      Hi, I’m sorry for the delay but I am not around all the time. I hope you were able to figure this out. If the puff pastry sheets weren’t able to be spread out/peeled off each other then you would have to start over with a new pack.

  40. Janis
    10/10/2016 at 8:01 pm

    Do you roll out the puff pastry before cutting?

    • Julie
      10/11/2016 at 6:39 am

      The puff pastry I get is folded into thirds so I just unfold it and cut. I don’t actually roll it out with a rolling pin.

  41. tanya
    10/21/2016 at 5:26 pm

    which brand and type of gruyere cheese did you use?

    • Julie
      10/22/2016 at 1:36 pm

      I used a wegman’s type brand of gruyere and it was medium.

  42. kay
    10/22/2016 at 4:52 pm

    can this recipe be made ahead of time? can it ne frozen

    • Julie
      10/23/2016 at 4:56 pm

      Yes, you can make this ahead of time. I would keep the topping separately from the puff pastry and assemble right before you serve. I haven’t ever tried freezing this so I’m not sure it would work.

  43. Casey
    11/22/2016 at 12:22 pm

    My husband hates mushrooms and I was wondering if there is another vegetable that could be substituted for this or if I left the mushroom out if it altogether, would it still be good?

    • Julie
      11/23/2016 at 6:58 am

      It would still be just as good if you left out mushrooms.

  44. Laura
    11/22/2016 at 5:14 pm

    I am hoping to make these for thanksgiving but I am heading to my sister in laws which is 2 hours away. I know that you mentioned that you can make the filling ahead of time – I wanted to find out when you state that you can also make the puffy pastry ahead of time, do you literally just cut it into squares and bake plain, and then once I reach my destination, assemble them by putting the filling on the already baked puffy pastry and reheat them so that they are warm. If this is correct, what would be the adjusted bake time? I am assuming that I would not need to bake them for the full 25 minutes if the puff pastry are already cooked or is that not correct? I am just not sure how much room she will have in her oven.

    • Julie
      11/23/2016 at 6:57 am

      Hi yes, that’s exactly what I’m talking about! I would wrap the entire baking dish with foil so it doesn’t overcook/burn the puff pastry too much. You would probably just need to cook it for 10 minutes to warm it through. I’d microwave the filling a bit before you put it on the puff pastry to guarantee that the filling gets completely warmed through.

  45. alanna
    11/23/2016 at 12:28 pm

    Hi! I am making this for Thanksgiving ( tomorrow, eek!) and have been searching high and low for puff pastry. I can’t find it in ANY stores here! Do you have a recommendation for a substitute? I was thinking crescent rolls but starting to panic :) thank you!!

    • Julie
      11/23/2016 at 3:41 pm

      That’s a bummer! You could use crescent rolls but keep in mind that since this recipe calls for puff pastry, then the flavor and texture of the puff pastry is going to be a big part of the dish so I can’t guarantee that it will be good with crescent rolls. Certainly can’t hurt to try! I’m sure it’d still be delicious either way :)

  46. Martha Alvarez
    02/10/2017 at 7:09 pm

    Is it really only 1 and 1/2 oz gruyere cheese? That seems like so little for this entire recipe.

    • Julie
      02/11/2017 at 8:58 am

      Yep, it is! However, you can feel free to use more because who doesn’t love extra cheese! :)

  47. Me
    03/27/2017 at 7:56 am


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