Preheat oven to 400º f
Combine ground beef, onion, milk, bread crumbs, quick oats, egg, and spices together, set the meat mixture aside
Spread ⅓ of enchilada sauce on the bottom of a 9x9 inch oven safe dish/pan
Scoop or roll the meatball mixture into 1 ½ tablespoon-sized balls and arrange in a single layer over the enchilada sauce, make about 20 meatballs
Pour remaining enchilada sauce over meatballs
bake in preheated oven for 35 minutes
Remove from oven and sprinkle with cheese
Bake an additional 10 minutes, until the meatballs are done through (internal temperature should reach 160-165º
Serve over rice or as desired