To make the filling: heat the oil in a large skillet over medium-high heat. Add the onion and sauté for 4 minutes. Add the ground beef and brown until no longer pink.

Add the bell pepper, salsa sauce, taco seasoning, oregano, salt and black pepper to taste. Cook until beef is cooked through and peppers and onions are tender, stirring occasionally. Set aside.

Preheat oven to 350 degrees F. Spread 1/2 cup of the enchilada sauce evenly along the bottom of a 9 x 13-inch baking dish.

To assemble the enchiladas: warm the tortillas according to the package directions.

Lay the tortilla on work surface. Spread about 3-4 tablespoons of the beef mixture on the middle of each tortilla. Sprinkle with cheese.

Roll up the tortilla and place seam side down in the baking dish in a single layer.

Pour the remaining enchilada sauce over them and sprinkle with the remaining cheese.

Cover the dish with aluminum foil. Bake in the preheated oven for 15 minutes. Remove the foil and bake for another 15 minutes.

Garnish with chopped cilantro and serve with toppings of your choice.