Mushroom & Swiss Burger Recipe

Mix and shape patties

Place the ground beef in a large bowl. Add Worcestershire sauce, kosher salt, black pepper, and garlic powder. Gently mix with your hands or a fork until just combined—do not overwork. Divide into 4 equal portions (about 4 oz each). Shape each portion into a round patty about 3/4 inch thick and make a slight indentation in the center of each patty with your thumb (this helps burgers cook evenly).

Preheat a heavy skillet or cast-iron pan over medium-high heat for 3–4 minutes until very hot. Add the vegetable oil and swirl to coat.

Cook the patties: place patties in the hot pan, indentation-side up. Cook undisturbed 3–4 minutes until a brown crust forms, then flip and cook another 3 minutes for medium (adjust time for desired doneness). During the last 1 minute of cooking, top each patty with a slice of Swiss cheese and cover the pan with a lid to melt the cheese. Remove patties to a plate and tent with foil to rest while finishing other components.

Prepare vegetables: thinly slice the mushrooms and slice the onion into half-moons. If using fresh thyme, strip the leaves from the stems.

Heat a separate large skillet over medium heat. Add butter and olive oil. When the butter foams, add the sliced onions and a pinch of salt. Sauté 4–5 minutes until they begin to soften and become translucent.

Add the sliced mushrooms and continue cooking, stirring occasionally, 6–8 minutes until mushrooms release their moisture and it evaporates and both mushrooms and onions are golden brown.

Stir in the thyme, soy sauce, remaining 1/2 tsp salt, and 1/4 tsp black pepper. Cook 1–2 minutes more so the flavors meld. Taste and adjust seasoning. Remove from heat and keep warm.

Toast buns: melt 1 tablespoon butter in a clean skillet over medium heat. Split the buns and place cut side down in the skillet. Toast 1–2 minutes until golden and crisp. Remove and set aside.

Make sauce: in a small bowl mix mayonnaise and Dijon mustard until smooth. Spread about 1 tablespoon of the sauce on each bottom bun.

Assemble burgers: place a lettuce leaf (if using) and a slice of tomato on each bottom bun. Top with a Swiss-topped burger patty, spoon a generous portion of the mushroom & onion mixture over the cheese, then place the top bun. Serve immediately.

Serve suggestion: serve with fries or a side salad and pickles. Remaining mushroom mixture keeps refrigerated in an airtight container for up to 3 days.