Preheat your oven to 350°F (175°C).
In a large skillet over medium heat, cook the diced onion until translucent, about 3-4 minutes.
Add the minced garlic and ground beef to the skillet. Cook until the beef is browned, breaking it apart with a wooden spoon, about 5-7 minutes.
Stir in the cumin, chili powder, salt, and black pepper. Mix well and let it cook for another 2-3 minutes.
Remove the skillet from the heat and stir in 1 cup of the enchilada sauce and 1 cup of the shredded cheese until combined.
Spread a thin layer of enchilada sauce on the bottom of the 9x13 inch baking dish.
Place about ¼ cup of the beef mixture into each tortilla, roll them up tightly, and place them seam-side down in the baking dish.
Pour the remaining enchilada sauce over the top of the rolled tortillas. Sprinkle the remaining cup of shredded cheese over the sauce.
Cover the dish with aluminum foil and bake in the preheated oven for 20 minutes. Remove the foil and bake for an additional 5 minutes, or until the cheese is melted and bubbly.
Allow the enchiladas to cool slightly before serving. Garnish with chopped fresh cilantro if desired and serve with sour cream on the side.