Preheat the oven to 350°. Without separating rolls, cut the rolls horizontally in half, and arrange the bottom halves in greased 1x9 inch baking pan.
Sprinkle with 1 cup of cheese. Bake until the cheese is melted about 3 to 5 minutes.
In a large skillet, cook the beef and onion over medium heat until the beef is no longer pink and the onion is tender, Break up the beef into crumbles about 6 to 8 minutes. Drain.
Stir in the tomatoes, Worcestershire sauce, mustard, salt and pepper. Cook and stir until combined about 1 to 2 minutes.
Spoon the beef mixture evenly over the rolls. Sprinkle with the remaining cheese. Top with bacon. Replace the tops.
Bake uncovered, until golden brown and heated through for about 20 to 25 minutes.