Heat an oven-safe skillet over medium-high heat.
Add 1 tbsp olive oil and cook the steak, garlic salt, and pepper.
Add the sliced steak to the skillet.
Sprinkle in the garlic salt and pepper. Stir to coat.
Allow the steak to fry until browned on all sides.
Reserve 1 tbsp of liquid from the skillet and discard the rest.
Cook the vegetables in the reserved liquid until the vegetables are cooked but the green pepper slices are still crisp.
Place 4 slices of White American cheese on top and a layer of the steak and vegetables.
Repeat the layers and top with the remaining cheese slices.
Place the oven-safe skillet in the oven and bake for 22-24 minutes.