Wagyu Smashburger Recipe

Make quick pickles

In a small heatproof bowl or jar combine white vinegar, water, sugar, kosher salt and mustard seed (if using). Stir until sugar and salt dissolve. Add thin cucumber slices, pressing them down so they are submerged. Let sit at room temperature for at least 20 minutes (longer for stronger flavor). Refrigerate if making ahead. Drain briefly before assembling the burger.

Prepare sauce

In a small bowl whisk together mayonnaise, ketchup, Dijon, sweet pickle relish, apple cider vinegar, Worcestershire sauce, smoked paprika, garlic powder and salt. Taste and adjust seasoning. Chill in refrigerator while you prepare the other components to let flavors meld.

Caramelize onions

Heat a skillet or griddle over medium-high heat and add 1 tablespoon neutral oil or butter. Slice the yellow onion into 1/4-inch rings and separate. Add onions to the hot pan, spread into an even layer and let cook undisturbed 2–3 minutes until browned on the bottom. Stir and continue to cook, reducing heat to medium-low if they start to burn, for a total of 8–12 minutes until deeply golden and softened. Season with 1/4 tsp salt and a pinch of black pepper. Remove from pan and keep warm.

Portion and shape patties

Divide the 1 lb wagyu ground beef into four equal portions (about 4 ounces / 113 g each) and gently roll into loose balls. Do not overwork the meat. Keep them loosely packed so they smash easily.

Preheat griddle or cast-iron skillet

Preheat a large cast-iron skillet or griddle over medium-high heat until very hot. Add 2 tablespoons neutral oil and spread to coat the surface. The pan should be smoking slightly for a proper smash.

Smash and sear

Place two meat balls on the hot griddle (work in two batches). Using a heavy spatula or a dedicated smash burger press (cover spatula with parchment if desired), press each ball down firmly into a very thin patty about 1/4 inch thick. Hold pressure for 10–15 seconds to create good contact. Season the exposed surface immediately with a light pinch of kosher salt and a grind of black pepper. Cook without moving 2–3 minutes until deep brown and crisp around the edges.

Flip and cheese

Using a thin spatula, scrape underneath to loosen and flip patties. Immediately top each patty with a slice of cheddar cheese (one slice per patty). Cook the second side 45–60 seconds until cheese begins to melt and the burger is cooked through (thin smash patties cook quickly).

Repeat for second patties

Repeat the smashing and cooking process for the remaining two meat balls so you end up with two double-stacked patties per burger (or assemble two patties per burger as described).

Toast buns

Split brioche buns and spread softened butter on cut sides. Toast buttered sides on the hot griddle or in a separate skillet until golden and lightly crisp, about 30–60 seconds. Remove and keep warm.

Assemble burgers

On the bottom bun spread about 1 tablespoon of Wild Rose secret sauce. Place a lettuce leaf if using, then stack one cheese-topped patty, followed immediately by the second cheese-topped patty to make a double. Pile a generous spoonful of grilled onions on top of the patties, add 4–6 slices of the quick pickles, and 1 tablespoon more sauce on the top bun. Crown with top bun and press gently to set. Serve immediately.