Preheat oven to 350 degrees Fahrenheit.

Grease a large roasting pan or Dutch oven with oil spray. Spread the onions, shallots, zucchinis, and mushrooms over the bottom.

Place the chicken on top of the vegetables and drizzle with olive oil. Sprinkle Italian seasoning over everything.

Prepare the sauce: In a bowl, mix together the tomato sauce, tomato paste, basil, parsley, garlic, and broth. Pour over the chicken.

Cover tightly and bake for two and a half hours. Raise the temperature to 420 degrees Fahrenheit, uncover, and bake for another 15–20 minutes, until browned at the edges.