In a skillet over medium heat, cook ground beef until browned and cooked through. Drain excess fat.
Stir in ketchup, mustard, Worcestershire sauce (if using), salt, and pepper. Cook for 2–3 more minutes.
Remove from heat and stir in half of the cheese until melted into the beef mixture.
Warm the tortillas in a dry skillet or microwave.
Spoon equal amounts of the cheesy beef mixture onto each tortilla. Top with lettuce, tomato, onion, and a sprinkle of remaining cheese.
Fold in the sides of the tortilla and roll up tightly to form a wrap.
Optional: Grill the wraps in a pan with a little oil for a crispy finish.