Heat olive oil in a large skillet over medium-high heat.
Add the sliced onion and bell pepper, cooking until softened, about 5 minutes. Season with garlic powder, salt, and pepper. Remove the vegetables from the skillet and set aside.
In the same skillet, add the thinly sliced ribeye steak. Cook for about 3-4 minutes, stirring occasionally, until browned and cooked through.
Return the cooked vegetables to the skillet and mix well with the steak.
Divide the steak and vegetable mixture into four portions in the skillet. Place two slices of provolone cheese on each portion and cover the skillet with a lid. Allow the cheese to melt for about 2-3 minutes.
While the cheese is melting, lightly toast the hoagie rolls in a separate pan or under the broiler until golden brown.
Once the cheese has melted, use a spatula to transfer each portion into a toasted hoagie roll. Serve immediately.