Fresh Italian parsley or thyme as optional garnish
Preheat oven to 350º F. Heat oil to medium-high heat in a large non-stick pan or skillet. Add onion and cook 4–6, stirring often until softened.
Stir in Italian sausage, ground beef, salt, pepper and Italian seasonings. Cook 7–10 minutes more, breaking up meat as it cooks, until browned. Drain excess oil then place mixture in a large baking or casserole dish.
Heat bell pepper and mushrooms in pan, 4–6 minutes until softened. Stir vegetables and spaghetti sauce with meat in casserole dish, sprinkle top with with mozzarella.
Separate biscuit dough pieces, flatten slightly and cut in half. Arrange on top of cheese; touching but not overlapping. The size of pan affects how many pieces fit on top. Bake 18–20 minutes or until biscuits are golden brown.
Remove from oven and let sit 5-10 minutes. Garnish with fresh herbs and serve.