In a mixing bowl, combine 1 pound of ground beef with 1 teaspoon each of garlic powder and onion powder, along with 1 teaspoon of Worcestershire sauce. Season with salt and pepper to taste. Gently mix the ingredients without overworking the meat, then shape the mixture into two ¾-inch thick patties, creating a small indentation in the center.

Heat a skillet over medium heat and add 2 tablespoons of softened butter along with 1 tablespoon of olive oil. Once melted, add ½ cup of sliced onions and sauté for about 3-4 minutes until they begin to soften. Next, add 1 cup of sliced mushrooms, cooking for an additional 5-7 minutes until they’re tender and caramelized. Season with salt and pepper, and remove from heat.

In the same skillet, increase the heat to medium-high and add the prepared beef patties. Cook the patties for about 4-5 minutes on each side until they reach a desirable doneness, ideally around 160°F for medium-well. During the last minute of cooking, layer 4 slices of Swiss cheese over the patties, allowing them to melt beautifully.

While the patties cook, butter one side of each of the 4 slices of bread. In another skillet or griddle, place the slices butter-side down and toast for approximately 2-3 minutes per side, or until they are golden brown and crisp.

Take two slices of the toasted bread and layer each with a beef patty topped with the sautéed mushrooms and onions. Place the remaining toasted bread slices on top, ensuring the buttered sides are facing out.

Carefully transfer the assembled sandwich to a skillet over medium heat. Grill each side for 2-3 minutes, pressing down gently to help the cheese melt, until the bread is golden brown and crispy.

Once grilled to perfection, remove the Mushroom Swiss Patty Melt from the skillet and slice it in half for easy handling. Serve immediately.