The Lamb Burger Recipe

Combine apple cider vinegar, water, sugar, and kosher salt in a small saucepan and bring to a gentle simmer, stirring until the sugar and salt dissolve.

Place the thinly sliced red onion in a heatproof jar or bowl. Pour the hot pickling liquid over the onions so they are submerged. Let sit at room temperature for 20–30 minutes, stirring once. For best flavor, chill at least 1 hour before serving. Keep refrigerated up to 1 week.

In a small bowl combine mayonnaise, lemon juice, D'Espelette pepper, grated garlic, olive oil and kosher salt. Whisk until smooth and adjust seasoning. Chill while you cook the patties. (Can be made a day ahead.)

Place ground lamb in a large bowl. Add minced shallot, minced garlic, chopped parsley, Dijon mustard, ground cumin, smoked paprika, kosher salt and black pepper.

Gently mix with your hands or a spoon until just combined—do not overwork the meat (about 20–30 seconds).

Divide the mixture into 2 equal portions and form into patties about 3/4-inch thick, making a slight dimple in the center of each to prevent doming while cooking.

Heat a heavy skillet or cast-iron pan over medium-high heat. Add 1 tablespoon olive oil and swirl to coat.

When the pan is hot and oil is shimmering, add the patties (do not overcrowd). Cook undisturbed 3–4 minutes on the first side until a deep brown crust forms.

Flip the patties and immediately top each with 2 slices of Gouda. Continue cooking 3–4 minutes for medium (internal temperature about 145°F / 63°C) or until desired doneness. If pan is smoking, reduce heat to medium.

Remove patties from the pan and let rest on a plate tented loosely with foil for 3–5 minutes.

While patties rest, butter the cut sides of the buns and toast them face down in the same skillet over medium heat until golden, about 1–2 minutes.

Spread a generous tablespoon of D'Espelette aioli on both bun bottoms and tops (adjust to taste).

Place the rested lamb patty with melted Gouda on the bottom bun. Top with a handful (~1 cup) of arugula, then a few pickled red onion slices. Season arugula lightly with salt and pepper if desired.

Close the burger with the top bun and serve immediately. Leftover pickled onions and aioli can be refrigerated.