Crossbreed Burger Recipe

Make the sauce

In a small bowl, whisk together mayonnaise, ketchup, sweet pickle relish, Dijon mustard, lemon juice, Worcestershire sauce, salt, and black pepper until smooth. Drizzle in truffle oil and taste; adjust salt or truffle oil (add up to an additional 0.125 tsp) to preference. Cover and refrigerate while preparing other components to let flavors meld (at least 15 minutes).

Prep lettuce and onion

Shred lettuce finely and place in a small bowl. Finely mince the onion and either soak briefly in cold water for 5 minutes if you want milder bite, then drain, or use raw for a sharper flavor.

Toast buns

Heat a skillet or griddle over medium heat. Spread softened butter evenly on cut sides of buns. Add 1 tsp oil or a small knob of butter to the hot pan and toast buns cut-side down until golden brown, about 1–2 minutes. Remove and keep warm.

Divide and portion meat

Divide the 1 lb washugyu into four even portions (~4 oz / 113 g each) for thin smash patties. Roll each portion loosely into a ball—do not overwork the meat.

Preheat griddle or skillet

Heat a heavy cast-iron skillet or flat top griddle over high heat until very hot. Add neutral oil and spread to coat the surface. The pan should be smoking slightly for proper sear.

Smash and sear

Place one meat ball on the hot surface. Immediately press down firmly with a heavy spatula or a second flat pan to flatten the ball to about 1/4" (6 mm) thickness. Season the exposed top with a pinch of fine sea salt and a light sprinkling of black pepper. Cook without moving for 2–2.5 minutes until deep brown and edges are lacy and crisp.

Flip and cheese

Using a thin metal spatula, scrape under the patty and flip it. Immediately place a slice of Cooper Sharp (use half a slice if you prefer less cheese) on the hot patty so it melts. Cook the flipped side 45–60 seconds until just cooked through and cheese is melted. Repeat with remaining portions, working in batches if necessary. Season the cooked side lightly with remaining salt/pepper as needed.

Sauce and layering

Spread about 2 tablespoons of the truffle thousand island sauce on the bottom half of each toasted bun. Place the first cheesed smash patty directly on the sauce. If you prefer a double-stack (as traditional smash style), add a second patty on top of the first with additional cheese; otherwise place single patty.

Add toppings

Top the patty with a mound of shredded lettuce, then sprinkle about 1–2 tablespoons of the minced onion evenly over the lettuce. Add pickles if using.

Finish

Spread a thin layer (about 1 tsp) of sauce on the inside of the top bun and place it on the burger. Press gently to set. Serve immediately while hot and juicy.