How to Make Smash Burgers (Diner-Style Cast Iron Recipe)

Squish three roasted garlic cloves into a small bowl with a pinch of salt and mash them into a smooth paste with the back of a fork. The paste step matters - chunks of garlic won't disappear into the sauce later.

In a larger bowl, whisk two room-temperature egg yolks with a teaspoon of Dijon mustard until uniform. Drizzle in half a cup of extra virgin olive oil one tiny splash at a time, whisking constantly. The yolks and oil emulsify into a thick golden mayo. Stir in the garlic paste, a few dashes of Tabasco, a teaspoon of lemon juice, salt, and pepper. Cover and chill for at least 30 minutes while you cook.

Set up a mandolin on the thinnest blade setting. Hold one peeled white onion against the guard, keep your fingers clear of the blade, and slice in one steady motion. You want translucent rings that almost fall apart when you pick them up.

This is the texture you need for the onion crust later. Thick slices won't fuse with the beef during the smash. If you don't own a mandolin, use the sharpest knife you have and cut the onion in half through the root first so it sits flat on the board.

Set a 15-inch cast iron skillet over medium-low and lay your bacon strips across the surface in a single layer. Drop a flat iron press on top so the bacon stays in full contact and renders flat instead of curling.

Slide the press around every minute or so to keep things even. Flip the bacon once the bottom side releases cleanly and is the color of an old penny, then press again. Pull the cooked strips onto paper towels and leave every drop of rendered bacon fat in the pan. That fat is the cooking medium for the burgers and the toasted buns.

Portion 1.5 pounds of 90/10 ground beef into eight loose three-ounce balls. A digital scale takes the guessing out of this. Roll each one between your palms only enough to hold its shape - any extra compression squeezes out the juice and ruins the crust.

Crank the heat under the skillet up to medium-high and let the bacon fat get screaming hot, almost smoking. Drop a small mound of the shaved onions directly onto the iron in each spot where a burger will go. The onion bed is what creates the Oklahoma-style crust. Don't skip it and don't go light.

Drop one beef ball on top of each onion mound and immediately cover with a small square of parchment paper. Press straight down with the flat iron press as hard as you can and hold for two full seconds. The ball should flatten to about an eighth of an inch thick - paper-thin is the goal.

Lift the press and peel away the parchment in one motion. Season the top of each patty with a pinch of kosher salt, freshly cracked black pepper, and a small dusting of garlic powder. Now leave them alone. The patties need 90 seconds of contact with that hot iron to build the deep mahogany crust that defines a smash burger.

Slide a stiff metal spatula straight under each patty, scraping along the iron to keep the entire crust attached. Flip in one motion - the onions should now be welded to what is now the top of the burger.

Drop a slice of American cheese over each patty. Splash about a tablespoon of water into an empty corner of the skillet and immediately cover with the flat iron press or an upside-down bowl. The water flashes to steam, the steam envelops the cheese, and ten seconds later you have a glossy melt without overcooking the beef underneath.

Slide the cheesed patties off to a warm plate. Set brioche bun halves cut-side down in the remaining bacon fat and toast for about 30 seconds until golden and crisp on the cut face. The fat soaks into the bread and adds another layer of flavor.

Build from the bottom up: smear chilled garlic aioli on the bottom bun, lay down bib lettuce and two tomato slices, stack two smashed patties cheese-side-in, top with two half-strips of bacon and a few dill pickle chips, then crown with the top bun. Press gently to compress the stack. Serve right away while the cheese is still molten and the crust is at its crispest.