Heat an outdoor grill or grill pan over medium-high heat. Preheat the broiler.
Season the steak with salt and pepper, to taste. Grill the meat until it is medium-rare, about 3 to 4 minutes per side.
In a large bowl, whisk together the Worcestershire sauce, soy sauce, mustard, rosemary, and red pepper flakes. Set aside.
Remove the steak from the grill to a cutting board, cover it with foil, and allow it to rest for 5 minutes. Slice the steak thinly and toss the slices in the Worcestershire sauce mixture.
Spread the rolls open and arrange on a baking sheet. Sprinkle each roll with a 1/4 cup of the cheese and put them under the broiler until the cheese is melted and bubbling, about 1 to 2 minutes.
In a small bowl, whisk together the mayonnaise and hot sauce. Spread the mayonnaise onto the bottom of each roll. Put a quarter of the beef into each of the rolls. (Reserve 4 pieces of beef for the Round 2 Recipe Couscous Stuffed Tomatoes). Cover with the roll tops, cut in half and serve.