Step 1: Prepare all your ingredients. Thinly slice the ribeye steak against the grain. If needed, partially freeze the steak for 30-45 minutes to make slicing easier. Thinly slice the onion and bell pepper.
Step 2: Heat a large skillet or griddle over medium-high heat. Add 1 tablespoon of olive oil. Add the sliced onions (and bell peppers, if using) and sauté until they are softened and caramelized, about 8-10 minutes. Remove the vegetables from the skillet and set them aside.
Step 3: Increase the heat to high. Add the remaining 1 tablespoon of olive oil (or butter) to the hot skillet. Add the thinly sliced steak in a single layer, ensuring not to overcrowd the pan. Cook in batches if necessary. Season the steak generously with salt and black pepper.
Step 4: Cook the steak for only 1-2 minutes per side until it’s browned and cooked through. Avoid overcooking to keep the steak tender. Once cooked, return the caramelized vegetables to the skillet with the steak and mix everything together.
Step 5: Divide the steak and vegetable mixture into four equal sections on the skillet. Lay 2 slices of provolone cheese over each section. Cover the skillet with a lid or foil for 1-2 minutes, allowing the cheese to melt into a gooey, delicious blanket.
Step 6: While the cheese is melting, lightly toast the hoagie rolls. You can spread a thin layer of butter on the cut sides of the rolls and toast them cut-side down on a separate hot skillet or griddle for 1-2 minutes until lightly golden.
Step 7: Using a spatula, scoop one cheesy steak and veggie section into each toasted hoagie roll. Serve your ultimate steak sandwich immediately and enjoy!