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This butternut squash gratin is the perfect side dish for Thanksgiving. It’s creamy, flavorful, and easy to make. Plus, it’s a great way to use up seasonal ingredients like squash. Give this recipe a try and you’ll be sure to impress your guests!

overhead shot of butternut squash gratin out of the oven with uncooked butternut squash on a cutting board.
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I love making new side dishes for Thanksgiving. I know most people probably don’t because you run the risk of “ruining Thanksgiving” when you stray from your regular menu but I personally think that’s the fun in cooking. And honestly, Thanksgiving is the perfect time to try out new recipes and add them to your holiday spread. You may find a new go-to recipe! Additionally, I really don’t think anyone is going to seriously be so horrible and say you “ruined Thanksgiving” if something doesn’t turn out.

However, I can confidently say that this butternut squash gratin is equally successful as it is elegant and delicious. So, if you’re looking for a new side dish to try for Thanksgiving, look no further than this recipe!

What’s the difference between butternut squash gratin and potato au gratin?

They’re nearly the same thing but instead of scalloped potatoes, you’ve got butternut squash! Hearty and totally satisfying, with a hint of sweetness.

angled show of the finished butternut squash gratin

What You’ll Need

Check out the recipe card below for exact measurements.

  • Butternut squash – the star of the dish!
  • Butter – adds a delicious richness to this gratin. It pairs well with the butternut squash and helps to create a creamy, flavorful dish.
  • Olive oil
  • Leeks – it adds just a hint of onion flavor but leeks are mild and that’s why they’re used in this recipe so not to overpower the rest of the dish.
  • Garlic
  • Sage
  • Ground nutmeg – for that warm flavor.
  • Black pepper
  • Heavy cream
  • Gruyere cheese – a type of Swiss cheese that is know for its nutty, creamy flavor.
  • Breadcrumbs – the crunchy texture on top is my favorite!
  • Salt
a spoon digs into the butternut squash gratin

How to make butternut squash gratin

Remember to head to the recipe card for detailed instructions!

Preheat oven. Set the oven temperature to 375 degrees Fahrenheit as you prepare the rest of the dish. Lightly grease a casserole dish and set aside.

Prep the butternut squash. You’ll want to peel and slice the butternut squash thinly. When you get to the seed, cut in half and remove the seeds.

Sauté in a pan. Cook the leeks and garlic in olive oil and butter until softened. Add the cream and the seasonings to the pan.

Layer the butternut squash. Take the butternut squash slices and layer them, overlapping slightly, in the bottom of prepared casserole dish. Top with some of the leek cream mixture and some cheese. Repeat so you have three layers.

Cover and bake. Bake covered for 45 minutes then uncover and bake at a higher temp.

Top with sage leaves. Fry the sage leaves and top the gratin with the sage!

overhead shot of the butternut squash gratin portioned out onto white plates

Substitutions and variations

This recipe is very versatile and can be easily adapted to your liking. For example, if you’re not a fan of butternut squash, you can substitute another type of squash. Or, if you’re looking for a lighter version of this dish, you can substitute the cream for milk. There are endless possibilities for how you can adapt this recipe, so feel free to get creative!

  • Butternut squash: can be substituted with another type of squash like acorn or pumpkin
  • Butter: can be substituted with olive oil
  • Cream: can be substituted with milk
  • Gruyere cheese: can be substituted with another type of cheese
  • Breadcrumbs: can be substituted with panko or omitted altogether, although you’ll miss the texture completely
a large spoonful of butternut squash gratin is shown and you can see the beautiful layers and the cream sauce between.

Storage and reheating

This butternut squash gratin can be stored in the fridge for up to 3 days. Simply reheat in the oven or microwave when you’re ready to enjoy it. This dish can also be frozen for up to 2 months. Just thaw in the fridge overnight and reheat before serving.

Frequently Asked Questions

What’s the best way to thinly slice butternut squash? I always say, a sharp knife does the trick! If you have a mandolin, that works too but be careful – since butternut squash is meatier, you’ll have to use a little more force.

What should I serve with butternut squash gratin? It pairs well with roasted meats or vegetables. It would also be delicious served with a green salad. And of course, the perfect Thanksgiving side dish!

More butternut squash recipes

Cozy Vegan White Bean Soup

Pumpkin Wild Rice Soup

Instant Pot Lentil Soup with Squash

Instant Pot Autumn Harvest Butternut Squash Soup

4.67 from 3 votes

Butternut Squash Gratin

If you're looking for a new side dish to try for Thanksgiving, look no further than this butternut squash gratin. It's a delicious and elegant dish that is sure to impress your guests.
Prep Time: 20 minutes
Cook Time: 45 minutes
Total Time: 1 hour 5 minutes
Servings: 6


  • 1 ½ – 2 pounds (680 g) butternut squash, peeled and sliced into 1/8 inch thickness
  • 2 tablespoons (28 g) butter
  • 1 tablespoon olive oil
  • 2 leeks rinsed and sliced thinly
  • 1 tablespoon minced garlic
  • 15 sage leaves
  • ½ teaspoon nutmeg
  • ½ teaspoon black pepper
  • 1 cup (236 ml) heavy cream
  • ½ cup (66 g) gruyere cheese + 2 tablespoons more for topping
  • ½ cup (54 g) plain breadcrumbs
  • Salt to taste
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  • Preheat oven to 375 °F (191 °C)
  • Peel the butternut squash and thinly slice them (about 1/8th inch thickness). When you get to the part with seeds, cut them in half and remove the seeds
  • To a pan, heat the olive oil and butter. Add the leeks and garlic, a pinch of salt and sauté until the leeks turn soft.
  • Add the cream to the leeks, nutmeg, salt, pepper and let it cook for 2 minutes and switch off.
  • Grease a 10-inch baking pan preferably one that is shallow. Layer the butternut squash slices, so they overlap slightly in the bottom of the pan.
  • Top this with some leek-cream mixture, topped with some cheese. Now place another layer of butternut squash slices on top of the cheese and repeat it with cream and cheese. Do this so you have 3 layers. Now top with more cheese and breadcrumbs.
  • Cover the pan with foil and bake at 375 °F (191 °C) for 40 to 45 minutes covered.
  • Remove the foil and check if a knife inserted inside goes easily (to see if the squash is cooked)
  • Now bake again at 400 °F (204 °C) for 10 minutes until the top is slightly golden.
  • Remove and top with some fried sage leaves (to fry the sage leaves, simply fry them in butter or oil for 15-20 seconds until crispy.)


Serving: 1serving, Calories: 411kcal, Carbohydrates: 43g, Protein: 9g, Fat: 25g, Saturated Fat: 14g, Polyunsaturated Fat: 2g, Monounsaturated Fat: 8g, Trans Fat: 0.2g, Cholesterol: 67mg, Sodium: 202mg, Potassium: 1059mg, Fiber: 6g, Sugar: 9g

This website provides approximate nutrition information for convenience and as a courtesy only. Nutrition information can vary for a variety of reasons. For the most precise nutritional data use your preferred nutrition calculator based on the actual ingredients you used in the recipe.

The default measuring system for this website is US Customary. Unit conversions are provided for convenience and as a courtesy only. While we strive to provide accurate unit conversions, please be aware that there may be some discrepancies.

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