Preheat oven to 450 degrees F and grease a rimmed baking sheet with nonstick spray.
Heat the olive oil in a nonstick skillet over medium-high heat. Add the peppers and onions and saute for 3-5 minutes or until softened.
Mix the peppers and onions with the breadcrumbs, cheese, ½ cup chicken broth, egg, garlic, salt, pepper, oregano, and crushed red pepper flakes.
Add the meat and just combine. Do not over mix, but be sure seasonings are well dispersed.
Roll meatballs into 1-inch circles and place on the prepared sheet pan.
Pour reserved chicken broth around meatballs and bake for 25 minutes.
Heat 2 cups of homemade tomato sauce or your favorite jarred sauce over medium heat in a large skillet and add in the cooked meatballs. Gently toss the meatballs in the sauce and remove from heat. Serve with additional freshly grated Parmesan.
Ground beef or ground turkey may be substituted for ground chicken. These meatballs are great served without the tomato sauce as well. Serve meatballs and sauce with pasta if desired.