Step 1: Preheat the Oven
Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish.
Step 2: Cook the Pasta
Bring a large pot of salted water to a boil. Cook the pasta according to package instructions until al dente. Drain and set aside.
Step 3: Prepare the Taco Beef
In a large skillet over medium heat, cook the ground beef until browned.
Add the diced onion and garlic, cooking until softened.
Stir in the taco seasoning, salsa, diced tomatoes, corn, and black beans (if using). Let simmer for 5 minutes.
Step 4: Combine Ingredients
In a large mixing bowl, combine the cooked pasta, sour cream, and half of the cheddar and Monterey Jack cheeses.
Fold in the taco beef mixture until evenly combined.
Step 5: Assemble the Bake
Pour the mixture into the prepared baking dish.
Sprinkle the remaining cheeses evenly over the top.
Step 6: Bake
Bake in the preheated oven for 20-25 minutes, or until the cheese is melted and bubbly.
Step 7: Garnish and Serve
Remove from the oven and let cool for 5 minutes. Garnish with fresh cilantro, and serve warm.