In a skillet over medium-high heat, melt butter, add mushrooms and 1 tablespoon Worcestershire sauce. Cook for 5 minutes, then add broth and cook until evaporated.
Add minced garlic and black pepper to the mushrooms, cook for another few minutes, then remove from heat.
Mix ground beef with steak seasoning and 3/4 teaspoon Worcestershire. Divide and form into four patties.
Grill patties over medium-high heat for about 4-5 minutes per side. Add a slice of Swiss cheese on each during the last minute of grilling.
Place each burger on a bun, top with sautéed mushrooms and other preferred toppings before placing on the top bun and serving.