Beef Enchiladas

Preheat oven to 350°. In a large skillet over medium heat, heat oil. Add onion and cook until soft, 5 minutes. Stir in garlic and cook until fragrant, 1 minute more. Add ground beef and cook until no longer pink, about 6 minutes. Drain fat.  Return beef mixture to skillet over medium heat. Add chili powder and cumin and season with salt and pepper, then stir in enchilada sauce. Bring to a simmer and cook until sauce thickens slightly, about 3 minutes. Remove from heat and stir in corn and black beans.