Saute onion in oil and one tablespoon of butter 5 to 8 minutes. Add mushrooms and cook 3 to 4 minutes. Remove from heat. Add sprouts, salt and pepper. Spread in buttered 1 1/2 quart casserole. Saute garlic in 2 tablespoons butter 2 or 3 minutes. Add 1/4 cup sharp cheddar, breadcrumbs and sprinkle mixture on sprouts. Bake at 400 degrees for 20 to 25 minutes. recipe makes 4 to 6 servings