Onion Wagyu Sliders Recipe

Form patties

Divide wagyu into 8 equal portions (about 2 oz each) and gently form into thin patties slightly larger than the buns. Do not overwork the meat; press a shallow dimple in the center of each patty to prevent puffing.

Season

Season both sides of each patty lightly with the fine sea salt and freshly ground black pepper just before cooking.

Cook patties

Heat a large skillet or cast-iron pan over medium-high heat until hot. Add 1 tablespoon neutral oil and swirl. Working in batches if necessary, add patties to the hot pan and sear 1.5–2 minutes per side for medium-rare to medium (internal ~125–135°F / 52–57°C). If you prefer cheese melted on top, place a slice of brie on each patty during the last 30–45 seconds and cover the pan briefly to melt. Transfer cooked patties to a plate and tent with foil to rest for 5 minutes.

Cook onions

Heat a wide skillet over medium-low heat. Add butter and olive oil until butter melts and foams. Add the thinly sliced onions in an even layer and stir to coat.

Caramelize

Cook the onions slowly, stirring every 3–5 minutes so they brown evenly. After 15–20 minutes they will have softened and begun to brown; add the brown sugar, balsamic vinegar, salt, and pepper. Continue cooking another 10–15 minutes until onions are deeply golden and jammy. Remove from heat and keep warm. Total time about 30–40 minutes.

Mix mayo

In a small bowl combine the mayonnaise, chopped parsley, chives, thyme, lemon juice, Dijon mustard, grated garlic, salt, and pepper. Stir until smooth and taste; adjust salt or lemon for brightness. Chill until assembly.

Toast buns

Split the slider buns and lightly butter the cut sides with about 1 tablespoon total butter. Toast in a skillet or under a broiler until golden and crisp, about 1–2 minutes. Watch closely so they do not burn.

Slice brie

If not already sliced, cut the brie into thin, small rounds roughly the diameter of the patties. Remove rind if desired for a smoother bite.

Spread about 1 teaspoon of the herb slider mayo onto the bottom half of each toasted bun.

Place an optional small handful of baby arugula or microgreens atop the mayo if using.

Set a wagyu patty (with melted brie if applied) on top of the greens. Top the patty with 1–2 tablespoons of warm caramelized onions.

Sprinkle a small pinch of flaky sea salt over the onions and cheese to enhance flavor.

Cap with the top bun, press gently, and serve immediately while warm. Repeat to make remaining sliders.