Park Recipe

Make the aioli

In a small bowl, combine 1/4 cup mayonnaise, 1 finely grated garlic clove, 1 tsp lemon juice, 1/2 tsp Dijon mustard, 1/2 tsp extra-virgin olive oil, 1/8 tsp salt and a pinch (about 1/16 tsp) freshly ground black pepper. Whisk until smooth. Taste and adjust salt or lemon for brightness. Refrigerate until assembly.

Sauté mushrooms

Heat 1 tbsp unsalted butter and 1 tsp olive oil in a medium skillet over medium-high heat until shimmering. Add 8 oz thinly sliced cremini mushrooms in an even layer (do not overcrowd—work in batches if needed). Let mushrooms brown without stirring for 2 minutes, then stir and continue cooking 3–4 minutes until deeply browned. Add 1 minced garlic clove and 1/2 tsp fresh thyme leaves, cook 30–45 seconds until fragrant. Season with 1/4 tsp salt and 1/8 tsp black pepper. Remove from heat and set aside.

Form patties

Divide 1 lb coarsely ground prime beef chuck into two equal portions (about 8 oz each). Gently form each into a loose 3/4-inch thick patty slightly larger than the bun diameter, handling the meat as little as possible to preserve juiciness. Make a shallow dimple in the center of each patty with your thumb to prevent doming during cooking.

Season and cook

Season both sides of the patties with 1 tsp kosher salt and 1/2 tsp freshly ground black pepper, pressing seasoning lightly into the meat. Heat a heavy skillet or cast-iron pan over medium-high until very hot (a drop of water should sizzle and evaporate). Add 1 tbsp softened unsalted butter to the pan and let it melt and foam. Add the patties and cook without moving for 3–4 minutes until a deep brown crust forms. Flip and cook another 3 minutes for medium-rare to medium (adjust time +/- 1 minute for preferred doneness). During the last 30 seconds, spoon any butter in the pan over the patty to baste and increase flavor. Remove patties to a plate to rest 3–5 minutes.

Prepare buns

Split 2 brioche buns and brush cut sides lightly with 1 tsp olive oil or a little melted butter. Toast cut sides in a skillet over medium heat until golden brown, about 1–2 minutes, or toast under a broiler for 30–60 seconds. Keep warm.

Assemble burgers

Spread a generous tablespoon of the garlic aioli on the bottom half of each toasted brioche bun. Place a handful (about 2–3 tbsp) of sautéed cremini mushrooms on top of the aioli. Add the rested beef patty on top of the mushrooms. If using, add a small handful (about 1/8–1/4 cup) of baby arugula on the patty for brightness. Spread a little aioli on the top bun and close the burger. Serve immediately.