Created by Kittencal on December 17, 2011
Step 1: Set oven to broiler heat. Place the toasted bun halves on a baking sheet.
Step 2: Lghtly spread with mayonnaise then mustard. Layer as follows starting with roast beef then sliced tomato, red onion, salt, pepper the sliced cheese on top. Broil 3-6 inches from the heat for about 2-4 minutes or until the cheese has melted and is lightly browned (keep an eye on it this will brown fast).