Heat olive oil in a large skillet or Dutch oven over medium-high heat.
Season chicken with salt and pepper, then sear both sides until golden brown. Remove and set aside.
In the same pan, sauté onions, bell peppers, and mushrooms until softened.
Add garlic and cook for 1 minute.
Stir in crushed tomatoes, chicken broth, herbs, bay leaf, and optional capers or olives.
Return chicken to the pan, cover, and simmer for 40 minutes or until chicken is tender.
Remove bay leaf, sprinkle with parsley, and serve hot.