Thin-sliced steak, melted cheese, onion rings on the side. A Philly cheesesteak dinner is a high calorie commitment you'll never regret making.
Preheat a large skillet over medium-high heat; add half the vegetable oil for sautéing.
Season thinly sliced ribeye with salt, black pepper, and garlic powder. Sauté steak in batches for 2–3 minutes until just browned, then transfer to a plate.
In the same pan, add sliced yellow onion, lower heat to medium, and cook until onions are soft and caramelized, about 10 minutes. Stir frequently to prevent burning.
Warm the hoagie rolls lightly in the oven. Top each roll with steak, caramelized onions, and 2 slices of provolone cheese. Place under a broiler for 2–3 minutes to melt cheese and crisp the bread.
For onion rings: Slice the remaining onion into thick rings. Set up breading station with flour, beaten egg with milk, and panko. Dip rings in flour, then egg-milk, then panko. Heat remaining oil in a deep skillet to 350°F, then fry rings in batches until golden brown and crisp, about 2–3 minutes per batch. Drain on paper towels and season with salt.
Serve the cheesesteaks hot with fresh onion rings on the side.