Make a 1 1/2- to 2-inch deep vertical cut around outside edge of each roll, leaving a 1/2-inch border. Remove tops of rolls, and discard. Hollow out about 1 1/2 inches of each bread roll, forming a boat. Set boats aside.
Cut steak diagonally across grain into 1/8-inch-thick strips; place in a small shallow bowl. Add dressing and crushed red pepper, tossing to coat; set aside.
Melt butter in a nonstick skillet over medium-high heat; add onion and mushrooms, and sauté 15 minutes or until onions are golden brown. Add bell pepper, and sauté 8 to 10 minutes or until bell pepper is tender. Add garlic, and sauté 1 minute. Remove mixture from skillet, and set aside.
Stir-fry steak mixture in skillet over medium-high heat 2 to 3 minutes or until steak strips are no longer pink.
Fill bread boats evenly with layers of steak mixture and onion mixture; top with cheese.
Broil 5 1/2 inches from heat 3 minutes or until cheese is lightly browned.