In large skillet over medium heat, cook and crumble beef and onions until no longer pink; drain. Stir in black beans and 1½ cans enchilada sauce.
Place 1/3 cup enchilada sauce in bottom of a 13x9-inch baking dish. Place ½ cup meat mixture and ¼ cup cheese in each tortilla; roll up. Place in baking dish; top with remaining enchilada sauce and cheese.
Bake in a preheated 375°F oven 30 minutes or until cheese is bubbly and golden brown.