Heat a medium skillet over medium heat. Add the diced bacon and cook until crisp. Remove to a paper towel lined plate. Drain off all of the bacon grease except 1 tablespoon. Add the ground beef and cook until browned and cooked through. Add the bacon back into the beef, and then stir in the ketchup and mustard.

Heat a griddle over medium heat. Put a layer of cheese on 2 of the tortillas. Add half of the meat mixture on top of each of the tortillas, followed by another layer of cheese. Top with the remaining tortillas. Grill until golden and until the cheese has melted, 5-10 minutes. Serve garnished with shredded lettuce and diced tomatoes.