Merriman's Smashburger* Recipe

Make patties

Divide the ground beef into 4 equal portions (about 5 oz each). Gently form each portion into a loose ball, then flatten into 3/4-inch thick discs slightly larger than your buns. Do not overwork the meat. Season both sides liberally with kosher salt and freshly ground black pepper just before cooking.

Prep produce and buns

Slice the Waimea tomato into 4 thick slices (~1/4-inch). Separate and dry butter lettuce leaves. Slice the yellow onion into 1/4-inch rings and separate into rounds. Split the poppyseed Kaiser buns and lightly butter cut sides with softened butter; set aside.

Grill onions and cook patties

Heat a large cast-iron skillet or flat top over medium-high heat until very hot. Add 1 tablespoon butter and a drizzle of oil if needed. Add onion rings and cook, turning occasionally, until deeply caramelized and golden (8–10 minutes). Remove onions and keep warm. Add the patties to the hot surface; press gently with a spatula for a classic smash contact, then cook 2–3 minutes until a deep brown crust forms. Flip and cook another 1–2 minutes for medium (adjust 30–60 seconds for desired doneness). Remove patties and keep warm.

Toast buns

Return skillet to medium heat, add remaining 1 tablespoon butter, and place cut sides of buns down. Toast until golden, about 30–60 seconds. Remove and set aside.

Assemble burgers

On the bottom bun spread 1 to 1-1/2 tablespoons of Special Sauce. Place a butter lettuce leaf, then the patty, a spoonful of aged cheddar cheese sauce, a slice of grilled onion, a tomato slice, and 2 pickle slices. Finish with additional Special Sauce on the top bun if desired and close burger. Repeat for remaining burgers.

Grate the cheddar finely. In a small saucepan over medium heat, melt 2 tablespoons butter. Whisk in 2 tablespoons flour and cook 1 minute to make a roux, stirring constantly. Gradually whisk in 1 cup whole milk, bring to a gentle simmer until thickened, about 2–3 minutes. Reduce heat to low and whisk in grated cheddar a handful at a time until fully melted and smooth. Stir in 1/2 teaspoon Dijon mustard, 1/2 teaspoon Worcestershire sauce, 1/4 teaspoon salt and 1/4 teaspoon black pepper. Keep warm on lowest heat or transfer to a small insulated container until service. If sauce becomes too thick, whisk in additional splash of milk to loosen.

In a small bowl combine 1/2 cup mayonnaise, 2 tablespoons ketchup, 1 tablespoon dill pickle relish, 1 teaspoon apple cider vinegar, 1/2 teaspoon smoked paprika, 1/4 teaspoon garlic powder, 1/4 teaspoon onion powder, 1/2 teaspoon sugar, and 1/4 teaspoon salt. Whisk until smooth and refrigerate at least 15 minutes to meld flavors. Taste and adjust seasoning.

Preheat oven to 425°F (220°C). Toss 1 lb baby potatoes (halved if larger) with 2 tablespoons olive oil, 1 teaspoon minced rosemary, 1 clove minced garlic, 3/4 teaspoon kosher salt and 1/2 teaspoon black pepper on a baking sheet in a single layer. Roast for 25–30 minutes, shaking pan halfway, until golden and crisp. Finish with a light sprinkle of flaky salt and transfer to serving dish alongside burgers.