Preheat your oven to 375 degrees. Spray a 9 by 13 inch baking dish with cooking spray and set aside.
In a large skillet over medium heat the olive oil.
Add the onion and green bell pepper and cook until softened, about four minutes.
Add in the ground beef and cook until no longer pink. Drain the fat from the pan and then stir in the taco seasoning.
To the prepared baking dish add the beef and vegetables, pinto beans, salsa, diced tomatoes, and diced chiles. Mix to combine and then spread to an even layer. Top with Fritos. Cover with cheese.
Bake for 10 minutes or until the cheese is bubbly. Top with tomatoes, lettuce, and sour cream.