Heat oil in a frying pan. Season steak with salt and pepper adding more or less to taste. Add steak to your warm frying pan and cook on medium heat for about 2 minutes on each side or until steak is cooked.
Remove steak from the frying pan and set aside. In the same pan over medium heat add butter and melt. Add in sliced peppers and onions and cook until tender. Once done remove from heat.
Preheat your oven to 400 degrees. Prepare a baking sheet with foil or nonstick cooking spray. Slice french bread in half and place on your prepared baking sheet. Spread mayonnaise evenly on each side half.
Slice steak and place it on your bread along with your cooked peppers and onions. Top both halves evenly with shredded mozzarella cheese. Bake for 10-15 minutes or until cheese is melted. Remove from the oven then slice and serve.
Notes
For this recipe, you can use any thinly sliced steak that you enjoy. I used a top round steak.