Step 1: Prepare the Filling : Heat olive oil in a large skillet over medium heat. Add onion and sauté for 2–3 minutes until soft and translucent. Add ground beef and cook until browned, breaking it apart with a spoon. Stir in garlic, cumin, chili powder, paprika, oregano, salt, and pepper. Add black beans and corn (if using). Stir well and cook for another 2–3 minutes. Remove from heat and let the filling cool slightly.
Step 2: Prepare the Tortillas : Preheat your oven to 375°F (190°C). Warm the tortillas slightly in the microwave or on a dry skillet — this makes them flexible and easier to roll.
Step 3: Assemble the Enchiladas : Spread about ½ cup enchilada sauce evenly on the bottom of a 9x13-inch baking dish. Place a tortilla on a flat surface and add 2–3 tablespoons of the beef and bean filling down the center. Sprinkle a little cheese over the filling. Roll the tortilla tightly and place it seam-side down in the baking dish. Repeat with the remaining tortillas and filling.
Step 4: Add Sauce and Cheese : Pour the remaining enchilada sauce evenly over the rolled tortillas. Sprinkle the top generously with cheese.
Step 5: Bake : Cover the dish with foil and bake for 15 minutes. Remove the foil and bake uncovered for another 10 minutes, until the cheese is melted and bubbly.
Step 6: Garnish and Serve : Let the enchiladas cool for 5 minutes before serving. Garnish with fresh cilantro, sour cream, avocado slices, and a squeeze of lime.