Make the Infusion: Mix the ingredients together and refrigerate to blend flavors.
Form the Burger Patties: In a bowl, combine the ground beef, salt, and pepper. Mix gently and form into patties, about ½ inch thick.
Cook the Mushrooms and Onions: Preheat a pan or skillet over medium-high heat.
Add the sliced onions and mushrooms to the pan or skillet. Sauté for about 5 - 7 minutes until softened and lightly browned. Remove and set aside.
Cook the Burger Patties: Place the patties on the pan or skillet. Cook for about 3 - 4 minutes on one side. Flip the patties and place a slice of Swiss cheese on each. Cook until the cheese is melted and the patties are cooked to your desired doneness.
Toast the Baguette: While the burgers are cooking, toast the baguette slices in a toaster until golden.
Prepare the Bruschetta: In a bowl, combine diced tomatoes, minced garlic, basil, balsamic vinegar, and olive oil to make the bruschetta topping. Mix well. Spoon the tomato mixture onto the toasted bread slices.
Assemble the Burgers: Assemble the burgers by spreading ketchup on the bottom bun, if using. Add the lettuce, tomato, and cooked patty with melted cheese, then top with sautéed mushrooms and onions.
Serve the burgers and bruschetta together, garnished with lime slices for the infusion. Enjoy your meal!