Preheat oven to 350℉.
In a large skillet over medium heat, cook beef, stirring frequently and breaking up meat with a spoon, until browned and cooked through. Stir in salt and pepper.
Wipe out skillet and place back over medium heat. Add bacon and cook, turning as needed, until browned and crisp. Transfer to a plate lined with paper towels to drain.
Lay tortillas on a large baking sheet, stacking 2 tortillas on top of one another for each taco. Divide beef between tortillas and top with cheese. Place in oven and bake until cheese is melted, about 5 minutes.
Before serving, top tacos with tomato, bacon, and lettuce.