Sean Brock's Crust Burger: A Smash Burger With an Inside-Out Bun

Chef Sean Brock's Crust Burger flips the standard smash burger on its head with one core move: the bun gets smashed and toasted so hard that its insides become the outside. The result is a wide, flat, lacy-edged burger wrapped in what looks more like a crispy pancake than a traditional roll. This walkthrough, filmed at the Food & Wine Classic, breaks down the full technique in under a minute.

The Technique

Start with a potato roll, buttered generously. Place it butter-side down on a heavy cast iron pan or flat griddle, then press it flat and toast both sides until deeply golden brown. The frames show buns pressed nearly flat on parchment, browned and smooth on the exterior, looking nothing like the soft rolls they started as.

For the patty, place ground beef directly on the hot surface and use two spatulas to smash it as thin as possible. The dual-spatula method gives you the leverage to get the meat paper-thin, which is the whole point. Season with salt and pepper while it cooks, then add sliced onions and a slice of American cheese. Scrape the patty up from the griddle, making sure to collect every bit of crust and lacy, craggy edge that formed against the iron.

The assembly inverts the bun: the toasted insides face out, creating a smooth, golden shell. Place the cheesy smash patty between the flipped bun halves, then press the whole sandwich back into the pan one more time for a final sear.

The Fancy Sauce

Brock's dipping sauce is simple and unapologetic: mayonnaise, ketchup, hot sauce, and a splash of fish sauce. The fish sauce is the unexpected ingredient that adds depth. Dip the burger rather than spreading the sauce inside.

Key Takeaways

• The defining move is smashing and toasting the potato roll so its soft interior becomes a crispy outer shell
• Two spatulas are essential for getting the patty thin enough to develop those signature craggy, lacy edges
• American cheese and onions go on while the patty is still on the griddle, before you scrape it up
• The assembled burger goes back into the pan for one final press
• The "fancy sauce" is four ingredients: mayo, ketchup, hot sauce, fish sauce