Instructions

1. In bowl of a food processor, pulse mushrooms until ground similar in size of beef. Remove any large pieces of mushrooms that didn’t get chopped. 
2. In a large cast iron skillet, heat olive oil over medium heat and saute ground mushrooms to remove water; season mushrooms with a little salt and pepper to taste. Transfer to a large bowl to cool. 
3. While mushrooms are cooling mix up burger seasonings in a small bowl. Alternatively, you can use your favorite premade burger seasoning. 
4. Meanwhile, prepare the mushroom topping by heating oil over medium low heat and sauteing onions and mushrooms until onions are caramelized, about 20 minutes. 
5. After minced mushrooms have cooled, add ground beef, burger seasonings, and Worcestershire to bowl. Gently mix ingredients together with hands taking care not to overwork the meat which can make burgers tough. 
6. Form 4 hamburger patties, ensuring sides are even and press a slight indentation in the center of the burger to help burgers to cook evenly and not puff up in the middle. Sprinkle each burger patty with additional burger seasonings, just before grilling. 
7. Heat grill or cast iron skillet. If cooking in skillet, add a little oil to pan and preheat over medium heat. Grill burgers until desired doneness is reached, should take a few minutes on each side. 
8. When burgers are almost finished, top each with swiss cheese, mushrooms and onions. Enjoy mushroom swiss burger on a bun or wrapped in lettuce with favorite burger toppings.