Prepare Ingredients: Thinly slice the ribeye steak, bell pepper, onion, and mushrooms.

Sauté Vegetables: Heat 1 tablespoon of oil in a cast iron skillet over medium-high heat. Sauté mushrooms until golden, then add onions and peppers. Cook until softened. Push vegetables to one side of the pan.

Cook Salami and Steak: Add salami to the empty side of the pan and cook until edges crisp. Push salami to the side with vegetables. Add remaining oil and cook the steak quickly over high heat until browned. Combine all ingredients in the pan.

Toast Rolls: Slice rolls lengthwise and toast with butter on a griddle or in the oven until golden.

Assemble Sandwiches: Layer cheese on the bottom half of each roll, add the steak mixture, and top with another slice of cheese. Close the sandwich and press lightly.

Serve: Slice diagonally and serve immediately.