5-6slicesof bacon cooked until crispy then crumbled,reserve bacon grease
Preheat oven to 400 degrees Fahrenheit. On a large baking sheet, place broccoli and cauliflower florets in an even layer and drizzle olive oil and garlic powder all over. Using your hands, mix it all together to get them evenly coated. Bake for 30 minutes.
While the broccoli and cauliflower is roasting, heat up the reserved bacon grease in a large pot. Once the grease is very hot, add 1 cup of sliced leeks to the pot and let them fry up until crispy, about 3 minutes. During this time, you'll want to watch this process very carefully because they can burn in an instant! Once leeks are crispy, remove from pot with a slotted spoon and drain onto a paper towel-lined plate. Set aside.
Once broccoli and cauliflower are done roasting, remove from oven and set aside.
In the same skillet used as before, add the remaining leeks and yellow onion. Sauté until softened. Then add the roasted broccoli and cauliflower.
Add the chicken broth and half and half to the pot and bring mixture to a low simmer.