Mushroom Burger Recipe

Form Patties

Divide the ground beef into two equal portions (about 8 oz each). Gently shape each portion into a patty about 3/4" thick and slightly wider than the bun. Avoid overworking the meat so patties remain tender.

Season both sides of each patty with kosher salt and freshly ground black pepper. Lightly brush or pat Worcestershire sauce onto both sides for extra umami.

Preheat a cast-iron skillet or grill over medium-high heat. Add 1 tablespoon vegetable oil to the skillet and let it heat until shimmering.

Cook the patties 3-4 minutes per side for medium (adjust time for desired doneness). Do not press down on the patties while they cook. In the last 1 minute of cooking, place two Swiss cheese slices (one per patty) over the patties and cover the pan or close the grill lid to melt the cheese.

Remove patties to a plate and tent loosely with foil to rest for 5 minutes while you finish mushrooms, onions, and toast buns.

While patties start or rest, heat a large skillet over medium heat. Add 1 tablespoon butter and 1 tablespoon olive oil; heat until butter foams.

Add thinly sliced onion and a pinch of salt. Sauté, stirring occasionally, until the onions begin to soften and caramelize, about 8-10 minutes. If onions start to brown too quickly, lower the heat.

Add sliced mushrooms to the skillet with the onions. Stir to combine and cook until mushrooms release their moisture and then begin to brown, about 6-8 minutes more.

Stir in minced garlic and fresh thyme leaves. Cook 30-60 seconds until fragrant. Season mixture with 1/2 teaspoon salt and 1/4 teaspoon black pepper, taste and adjust seasoning as needed.

If mixture is done before patties, transfer to a warm bowl and keep covered. For a saucier topping, stir in 1-2 tablespoons water or beef broth and simmer 1-2 minutes to deglaze pan.

While mushrooms are cooking or after resting patties, melt 1 tablespoon butter in a separate skillet over medium heat. Place bun halves cut-side down and toast until golden, about 1-2 minutes. Remove from heat.

If using condiments, spread desired amount on bun bottoms and/or tops.

Place a lettuce leaf and tomato slice (if using) on each bun bottom. Position the rested patty with melted Swiss on top of the tomato/lettuce.

Spoon a generous portion of the sautéed mushrooms and onions over each cheese-topped patty.

Close with the bun top, press gently, and serve immediately. Serve with fries or a side salad if desired.