Tex-Mex Beef and Tortilla Casserole

1 tablespoon of olive oil

1 sweet onion chopped

4 garlic cloves minced

1 green bell pepper chopped

1 1/2 pounds of lean ground sirloin

1 cup of fresh or frozen corn kernels

2 tablespoons of chili powder

1 teaspoon of ground cumin

1 teaspoon of dried oregano

1/4 teaspoon of ground chipotle pepper

2 (14.5-ounce) cans of petite diced tomatoes

1 teaspoon of salt

12-14 (6-inch) of corn tortillas

3 cups of shredded sharp cheddar cheese

1/2 cup of prepared salsa

1. Preheat the oven to 350°F. Lightly oil an 11- by 7-inch baking dish.
2. Heat the oil in a large nonstick skillet over medium. Add the onion and cook, stirring occasionally, until starting to soften, 4-5 minutes. Add the garlic and bell pepper and cook 2 minutes. Add the beef and cook, breaking into small pieces with a wooden spoon, until no longer pink, about 8 minutes. Drain off excess fat and return skillet to the stove; cook 2 minutes. Add the corn and cook 1 minute; stir in the chili powder, cumin, oregano and chipotle pepper and cook until well-distributed and fragrant, about 1 minute. Stir in the tomatoes, bring to a simmer and cook, stirring occasionally, until thickened, about 8 minutes. Season with salt.
3. Arrange a single layer of tortillas over the bottom of the prepared baking dish, cutting as necessary to make them fit. Spread 1/2 of the beef mixture over then tortillas then top with 1 1/4 cups of the cheese. Top the cheese with a layer of tortillas, cutting to fit as needed. Spread with the remaining beef mixture and 1 1/4 cups cheese. Top with remaining tortillas, cutting as needed. Then spread with the prepared salsa and sprinkle with the remaining 1/2 cup cheese.
4. Bake until cheese is melted and the filling is hot and bubbly, about 25-28 minutes. Let stand at least 10 minutes before cutting.