Preheat your oven to 350°F (175°C).

In a large skillet over medium heat, cook the ground beef, diced onion, and minced garlic until the beef is browned and the onion is translucent, about 5-7 minutes. Drain any excess fat.

Stir in the cumin, chili powder, salt, and black pepper. Cook for an additional 2 minutes, then remove from heat.

Spread 1/2 cup of the enchilada sauce on the bottom of a 9x13 inch baking dish.

To assemble the enchiladas, warm the corn tortillas in a dry skillet or microwave until pliable. Spoon about 1/4 cup of the beef mixture onto each tortilla, sprinkle with a little cheese, and roll them up tightly. Place seam-side down in the baking dish.

Once all the enchiladas are in the dish, pour the remaining enchilada sauce over the top and sprinkle with the remaining cheese.

Cover the dish with aluminum foil and bake for 20 minutes. Remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and golden.

Remove from the oven and let cool for a few minutes. Garnish with chopped cilantro if desired and serve with sour cream on the side.