Umami Burger Recipe

Whisk rice vinegar, water, sugar and salt in a small bowl until sugar dissolves. Add thinly sliced red onion, press down so onions are submerged, cover and refrigerate for at least 20 minutes (can be made up to 24 hours ahead). Drain before using.

Make the parm crisp

Preheat oven to 400°F (200°C) or use a skillet. Line a baking sheet with parchment. Sprinkle 3 tablespoons of grated parmesan in a 3–4 inch circle (leave gaps). Bake 5–7 minutes until golden and bubbly, then let cool to crisp. Alternatively, melt in a nonstick skillet over medium heat until set and flip to brown lightly. Make two crisps (use remaining parmesan if needed).

In a small bowl combine mayonnaise, truffle oil, lemon juice, grated garlic and salt. Stir until smooth. Taste and adjust salt or truffle oil. Refrigerate until assembly.

Heat 1 tablespoon butter in a skillet over medium-high heat until foaming. Add sliced mushrooms in a single layer and let brown without stirring for 2 minutes, then stir and cook 2–3 more minutes until deeply browned.

Add minced garlic and cook 30 seconds until fragrant. Deglaze pan with soy sauce and mirin, stirring to lift browned bits. Add 3 tablespoons umami sauce and stir to coat. Cook another minute until sauce reduces slightly. Remove from heat and keep warm.

Divide the ground beef into two equal portions and gently form into 3/4-inch thick patties slightly wider than the buns. Press a shallow dimple in the center of each to prevent doming. Season both sides with kosher salt and freshly ground black pepper.

Heat a heavy skillet or griddle over medium-high heat and add 1 tablespoon neutral oil. When shimmering, add the patties. Cook undisturbed 3–4 minutes until a crust forms, flip and cook 3–4 minutes for medium (adjust to desired doneness). During the last minute, spoon a little of the mushroom-umami pan sauce over patties to glaze.

While patties finish, spread softened butter on the cut sides of the brioche buns and toast cut-side down in a second skillet or on the griddle until golden, about 1–2 minutes.

If serving fries, bake or fry according to package or recipe instructions. For oven: toss fries with 2 tablespoons oil, spread on a sheet, bake at 425°F (220°C) 18–25 minutes flipping halfway until crisp. Season with 1/2 teaspoon salt immediately.

Spread about 1 tablespoon of truffle aioli on the bottom bun. Place a handful of arugula or lettuce on the aioli (this helps keep bun from getting soggy). Place the cooked beef patty on top.

Spoon 1–2 tablespoons of the mushroom-umami mixture over the patty. Add a small handful of pickled red onion (drained) on top of mushrooms.

Top with a parmesan crisp (break to fit if necessary). Drizzle 1 tablespoon umami sauce over the crisp and finish with freshly grated parmesan if desired.

Cap with the toasted top bun and serve immediately with the fries or daily soup of choice.