In a bowl, combine 1 pound ground beef chuck with 1 tablespoon Worcestershire sauce, 1 teaspoon granulated garlic, 1 teaspoon onion powder, 1 teaspoon kosher salt, and ½ teaspoon ground black pepper until all ingredients are well blended. Divide the mixture into four equal portions, shaping each into a burger patty.
Preheat your grill, grill pan, or skillet over medium-high heat. Once hot, carefully place the burger patties on the grill. Cook the burgers for about five to seven minutes on one side or until they develop a nice crust.
After flipping, cook the burgers for an additional five to seven minutes on the other side. To ensure they’re cooked to perfection, it’s recommended that the internal temperature reaches 160°F. During the last minute of cooking, place 1 slice of Swiss cheese on top of each patty.
While the burgers are cooking, melt 2 tablespoons of butter in a large skillet over medium heat. Add the sliced onions and sliced mushrooms. Stir frequently, cooking until the onions are caramelized and the mushrooms have turned golden brown, which should take about ten to fifteen minutes.
Season the sautéed onions and mushrooms with a sprinkle of salt and pepper to taste.
While the veggies are finishing up, toast the brioche hamburger buns on the grill or in a toaster oven until they’re lightly golden.
To assemble the burgers, place a cooked burger patty on the bottom half of each toasted bun. Top with the sautéed onions and mushrooms.
Add any additional toppings you desire, like lettuce, tomato, mayonnaise, or mustard.
Finish with the top half of the bun, gently pressing down to hold everything together. Each bite should be packed with flavors and textures!
Serve the Mushroom Swiss Burgers hot, and enjoy this delightful meal with family and friends!