Place the ground beef into a mixing bowl. Add salt, pepper, garlic powder, and onion powder. Mix gently without overworking the meat. Shape the mixture into four equal burger patties.

Heat butter and olive oil in a skillet over medium heat. Add the sliced mushrooms and garlic. Cook for about eight minutes until the mushrooms become golden, tender, and full of flavor.

Pour Worcestershire sauce over the mushrooms. Stir well for one minute. This adds extra savory flavor and helps the mushrooms develop a rich, delicious taste.

Heat a grill pan or skillet over medium-high heat. Cook each burger patty for about four to five minutes per side until nicely browned and cooked to your preferred doneness.

Place one slice of Swiss cheese on each cooked patty. Cover the skillet for one minute until the cheese melts smoothly over the juicy burgers.

Lightly butter the inside of each burger bun. Toast them in a clean skillet for about two minutes until they become golden and slightly crispy.

Spread mayonnaise and Dijon mustard on the toasted buns. Add lettuce, tomato, onion, the cheesy burger patty, and a generous spoonful of sautéed mushrooms.

Place the top bun over each burger. Serve while hot with your favorite side dishes. Enjoy the juicy beef, creamy cheese, and buttery mushrooms in every bite.