Mushroom Swiss Smash Burgers

Mushroom Swiss Smash Burgers

A blended smash burger (about 25%+ mushrooms with lean ground beef) cooked in a cast-iron skillet with Swiss cheese, a savory mushroom topping, and peppery arugula. Adapted from Whitney Reist at Sweet Cayenne.

Ingredients

• 6 oz baby bella (or mixed) mushrooms, wiped clean — for the burger blend
• 1 tbsp Montreal steak seasoning
• 1 tbsp Worcestershire sauce (for the blend)
• ½ tsp black pepper
• 1 lb lean ground beef (90/10 or 93/7)
• Avocado or canola oil, plus butter, for cooking
• 4 brioche hamburger buns
• 4 slices Swiss cheese (baby Swiss works well)
• Arugula, for serving
• 1 tbsp oil + 1 tbsp butter (for sautéed mushrooms)
• 6 oz bella mushrooms, wiped clean and sliced
• 1 tbsp finely minced shallot
• ½ tsp fresh thyme, finely minced
• 1 tbsp Worcestershire sauce (for the topping)
• 1 tsp hot sauce
• Salt and pepper, to taste

Method

1. For the blend: pulse the 6 oz mushrooms in a food processor in short bursts until finely chopped (like minced garlic), scraping the bowl as needed. Transfer to a large bowl; stir in steak seasoning, 1 tbsp Worcestershire, and black pepper. Add the beef and gently fold together with a spatula—don’t overwork. Divide into 4 loose mounds (about baseball-sized).
2. Toast the buns: heat a cast-iron skillet over medium-low. Add a drizzle of oil and a dab of butter. Toast buns cut-side down until golden, about 2 minutes. Transfer to a plate.
3. Sauté the topping: return the skillet to medium heat. Add sliced mushrooms and shallot with oil and butter; cook until golden. Stir in thyme, 1 tbsp Worcestershire, hot sauce, and salt and pepper; heat through about 2 minutes. Transfer to a bowl and cover to keep warm.
4. Smash and cook: wipe the skillet if needed, return to medium heat, and add a drizzle of oil. Place 2 beef mounds in the pan and smash firmly with a metal spatula to about ½-inch thick. Cook about 3 minutes until crisp at the edges, then flip. Top each with Swiss and cook about 3 minutes more (aim for ~155°F for medium-well). Tent with foil; repeat with remaining mounds.
5. Assemble: place each patty on a toasted bun, spoon on the mushroom mixture, add arugula, and serve hot.