Preheat oven to 450° F. Line Sheet Pan with Sheet Pan Liner.
In a sauté pan, heat oil over medium-high heat. Season steak with salt and pepper, to taste, if desired. Cook steak about 3–4 min, or until desired doneness. Remove from pan and set aside to rest.
Meanwhile, slice bell peppers and onion into thin strips. Place in pan; add vinegar and dressing mix. Cover; cook until tender, about 4 min.
In a Prep Bowl, combine butter and aioli mix. Split rolls in two and brush with garlic butter. Place on Sheet Pan and toast about 3–4 min.
Meanwhile, slice steak against the grain.
Evenly divide steak and veggies between toasted roll halves. Place on Sheet Pan, sprinkle with cheese and heat in oven until cheese is melted, about 1 min.