Spiralized Zucchini, Quinoa and Turkey Sausage Stuffed Peppers

bell peppers of assorted colors

Kosher salt and freshly ground black pepper

medium zucchini, spiralized or diced, about 4 cups

olive oil, divided

ground turkey

garlic, minced or pressed

dried fennel seed, crushed

crushed red pepper flakes

chopped yellow onion

crushed tomatoes or tomato sauce

cooked quinoa

grated Parmesan cheese plus more for garnish

chopped fresh basil