Heat a large skillet to medium heat (not medium-high yet—patience here creates better results) and melt 4 tablespoons of butter. Add your thinly sliced onion and stir frequently. This step takes 6 to 10 minutes, and you're looking for the onions to transform from raw and white to deeply golden and soft. The onions should look almost caramel-colored, and they'll smell sweet and complex rather than pungent. This isn't rushed cooking—low and slow allows the natural sugars to caramelize rather than burn. When they reach this stage, remove them to a clean plate and set aside. This critical first step cannot be hurried.

If your beef isn't already sliced paper-thin, slice it as thinly as possible now (a sharp knife or partially frozen beef makes this easier). Pat the beef dry with paper towels—this removes surface moisture that would prevent browning through steam. Sprinkle seasoning salt lightly across all surfaces, using a gentle hand. You're seasoning the exterior, not creating a salt crust. Remember, Worcestershire sauce adds significant saltiness, so you don't need heavy seasoning here.

Increase your skillet heat to medium-high and add the remaining butter plus 2 teaspoons of olive oil. Wait for the butter to foam slightly and the pan to reach proper temperature—you'll know because a single drop of water will sizzle and evaporate immediately. Add the beef in a single layer if possible (work in batches if needed—overcrowding prevents browning). This is critical: cook for only 1 to 2 minutes per side. You're not cooking it through; you're creating a golden crust. The beef will appear slightly underdone when you flip it, and that's exactly right. It will continue cooking when you add the sauce and cover it later. If you cook it fully now, it will be tough and dry by the time you assemble the sandwich.

Once the beef is browned but still slightly pink in the center, pour in ½ cup of Worcestershire sauce and 1 to 2 tablespoons of hot sauce if using. Stir constantly for about 60 seconds. You're doing two things: dissolving the flavorful browned bits (called fond) stuck to the pan bottom, and coating the beef with sauce. The acid in Worcestershire begins breaking down beef proteins slightly, which keeps them tender rather than firm.

Return your caramelized onions to the pan and stir everything together, making sure the onions distribute evenly through the beef. Now place your cheese slices directly on top of the mixture. Cover the skillet with a lid or even foil for about 60 to 90 seconds. The residual heat plus the covered environment creates a steamy microclimate that melts the cheese perfectly. The cheese should be completely melted and starting to get glossy—this is the point where the fat emulsifies with the sauce and creates that classic cheesesteak texture. If you prefer extra-cheesy sandwiches, add a second layer of cheese and re-cover for another 30 seconds.

While the cheese is melting, heat a separate griddle or skillet to medium-high heat. Spread a thin but visible layer of butter on the cut side of each roll. Place them butter-side down on the hot griddle and toast until they're golden brown and crispy, about 2 to 3 minutes. The butter creates a protective barrier that keeps the bread from absorbing too much of the mixture's moisture, which would make the sandwich soggy. This toasting step is why your homemade version will be better than many restaurant versions—most places don't toast their rolls properly.

Place each toasted roll on a serving plate, open-side up. Spoon the cheesesteak mixture generously onto each roll, making sure to include the melted cheese and sauce. Serve immediately while the heat keeps everything melty and the roll is still crispy. The contrast between the crispy exterior and creamy interior is part of what makes this sandwich special.