Step 1: Heat olive oil in a large skillet or cast iron pan over medium-high heat. Add the thinly sliced onion and bell peppers. Sauté until tender and slightly caramelized, about 8-10 minutes. Remove vegetables from the skillet and set aside.
Step 2: Increase heat to high. Add the thinly sliced steak to the same skillet. Cook, stirring frequently, until browned and cooked through, about 5-7 minutes. If cooking in batches, add a little more oil if needed.
Step 3: Return the cooked vegetables to the skillet with the steak. Season with garlic powder, onion powder, salt, and black pepper. Stir well to combine and heat through for 1-2 minutes.
Step 4: Lay out provolone cheese slices on a clean surface or a baking sheet lined with parchment paper. Spoon a portion of the hot steak and vegetable mixture onto one end of each cheese slice.
Step 5: Carefully roll up each cheese slice, enclosing the filling. You can serve them immediately as is, or for a slightly melted exterior, place the rolled-up cheesesteaks back into the warm skillet for 30-60 seconds per side until the cheese is slightly softened.