Combine mayonnaise, mustard and pepper in small bowl, whisk to combine. Spread mixture on cut sides of rolls. Place bottom rolls on baking sheet, divide pastrami evenly on bottom rolls, put 2 pieces of cheese on top of pastrami press down to adhere. Put baking sheet under broiler until cheese is all melted and hot. Remove from oven add a tomato slice and lettece and top of roll. Serve hot!