First prepare the leftover meatloaf by slicing into 1 inch thick slices.
Heat a large skillet over medium heat and lightly butter. Add meatloaf to the skillet and cook for a couple minutes. Flip meatloaf over and top with sliced cheese and continue to cook until cheese is melted.
Once the meatloaf is done, slice Hawaiian Rolls in half and lightly toast.
Spread mayonnaise on the rolls followed by ketchup. Top with meatloaf. Enjoy!