Cut rolls in half, and toast in a bread toaster. Place on a baking sheet. Spread each half with mayonnaise and mustard. Layer with roast beef, tomato, red onion, Provolone, salt and pepper.
Broil 3 to 6 inches from heat source for 2 to 4 minutes (keep a constant eye on it) until cheese is bubbly and is beginning to brown.
