Season the sliced steak with salt, pepper, onion powder, and garlic powder to taste.

Heat vegetable oil in a large skillet over medium-high heat. Add the steak, peppers, and onions. Sauté until the steak is fully cooked and the vegetables are tender.

Split the sub rolls and place them cut-side up onto a baking sheet. Place two slides of white American cheese onto each sub roll. Broil in the oven until the cheese has melted.

Add some of the cooked steak, onion, and pepper mixture into each sub roll.