Preheat broiler. Add the hoagie roll, open faced onto a baking sheet lined with foil. Broil until the bread is lightly toasted. Add two slices of provolone to each half of the bread.
Return to the broiler until the cheese is melted.
Heat 1 tbsp olive oil in a large skillet over medium heat. Add onions, seasoned with salt. Cook, stirring often, until onions are caramelized, about 12-15 minutes. Remove from the pan, and set aside.
Add peppers to the skillet, and sauté until soft. Remove from the pan, and set aside.
Add 1 tbsp oil, and cook the steak until it has reached your preferred level of doneness, about 5 minutes. Season with salt and pepper.
Return veggies to the skillet and toss to combine with the steak. Blanket mixture with provolone and cook, covered, until the cheese is melted, about 3 minutes more. Add the mixture on top of the hoagie rolls, and serve open faced with a fork and knife.