1. Place steak pieces on large plate or baking sheet and freeze until very firm about one hour.

2. Meanwhile, adjust oven rack to middle position and heat oven to 400°. Spread split roles on baking sheet and toast until lightly browned, 5 to 10 min.

3. Using sharp knife, shave steak pieces as thinly as possible against the grain mound meat on cutting board and chop coarsely with knife 10 to 20 times.

4 heat 1 tablespoon oil in 12 inch nonstick skillet over high heat until smoking. Add half of the meat in an even layer and cook without stirring until well browned on one side 4 to 5 min. sterling continue to cook until meat is no longer pink, 1 to 2 min. transfer meat to colander set in large bowl. Wipe out skillet with paper towel. Repeat with remaining 1 tablespoon oil and sliced meat.

5. Return now empty skillet to medium heat. Drain excess moisture from meat. Return meat to skillet (discard any liquid in bowl) and add salt and pepper. Heat, stirring constantly, until meat is warmed through, 1 to 2 min. reduce heat to low, sprinkle with Parmesan, and shingle slices of American cheese over meat. Allow cheeses to melt about 2 min. using heatproof spatula or wooden spoon, fold melted cheese into meat thoroughly. divide mixture evenly among toasted rolls. Serve immediately.