Mushrooms & Swiss Recipe

Prep

Clean mushrooms with a damp towel or quick rinse and pat dry; slice mushrooms about 1/4-inch thick. Peel and thinly slice the onion. Mince the garlic and strip thyme leaves if using.

Heat a large skillet over medium-high heat. Add the unsalted butter and olive oil. When butter is melted and foaming, add the sliced onions and sauté for 3–4 minutes until they begin to soften and turn translucent.

Add the sliced mushrooms to the pan in a single layer as much as possible. Let them cook undisturbed for 2 minutes to brown, then stir and continue to cook 4–6 minutes until mushrooms are browned and onions are caramelized.

Stir in the minced garlic, thyme, Worcestershire sauce, salt, and black pepper. Cook 1–2 more minutes until garlic is fragrant and any liquid released by mushrooms has mostly evaporated. Taste and adjust seasoning. Keep warm over low heat while you cook the patties.

Divide the ground beef into four equal portions (about 4 oz each) and gently form into patties about 3/4-inch thick. Make a shallow dimple in the center of each patty with your thumb to help them cook evenly. Season both sides with kosher salt and freshly ground black pepper.

Heat a heavy skillet or cast-iron pan over medium-high heat and add 1 tablespoon vegetable oil. When the oil is shimmering, add the patties leaving space between them. Cook undisturbed 3–4 minutes for medium-rare to medium (adjust time for desired doneness). Flip once and cook 3–4 minutes more.

About 1 minute before the patties are done, reduce heat to medium-low and place a slice of Swiss cheese on each patty. Cover the skillet with a lid or a piece of foil to melt the cheese, about 30–60 seconds.

Remove patties from the skillet and tent loosely with foil to rest for 2–3 minutes. If you prefer the mushrooms hot on the burger, rewarm the mushroom mixture briefly while patties rest.

While the patties cook or during their resting time, split the buns and spread softened butter on the cut sides. Toast the buns in a clean skillet or on a griddle over medium heat until golden brown, about 1–2 minutes per side.

To assemble: place lettuce (if using) on the bottom bun, add the Swiss-topped patty, spoon a generous portion of the sautéed mushrooms and onions over the cheese, add tomato slices and pickles if desired, spread mustard or mayo on the top bun, and close the burger.

Serve immediately with your choice of sides.