Add the beef broth to a large skillet over high heat. When the broth starts to steam, reduce heat to medium and add the roast beef and cover. Let warm for about five minutes, until the roast beef is no longer pink.

Meanwhile, preheat the oven broiler. Slice rolls in half and place them on a baking sheet cut side up. Spread a thin layer of mayonnaise on the top side of the buns and sprinkle with Italian seasoning.

When the roast beef is warm, remove it from the broth using a slotted spoon or tongs and divide between the rolls. Lay two slices of cheese over the roast beef on each roll.

Broil for 2-3 minutes, until bread is toasted and cheese is melted. Serve with extra broth for dipping.