Preheat oven to 350℉. In a large skillet cook beef, sausage, and onion until beef is browned and crumble; drain, and return to skillet.
Add spaghetti sauce, and cook over low heat approximately 10 minutes; stirring often.
Spoon meat mixture into a lightly greased 13x9-inch baking dish. Top with sour cream then sprinkle with cheese.
Unroll crescent rolls and place over cheese pinching seams together.
Bake 20-25 minutes or until crescents are cooked through.