In Dutch oven brown chicken in vegetable oil. Add onion and garlic and sauté until onion is tender. Stir in water, tomato sauce, drained mushrooms, oregano, salt, and hot pepper sauce. Cover and bake at 350° for 30 minutes.
Stir in spaghetti and bake 30 minutes longer, or until chicken and spaghetti are tender, stirring occasionally. Serve with Parmesan cheese, if desired.
This chicken and spaghetti recipe serves 4.