Start by heating a skillet over medium heat. Add a tablespoon of oil and the sliced onions, cooking them slowly. Stir occasionally, allowing them to soften and turn golden brown. This process takes about 15-20 minutes. Once they’re caramelized, set them aside.
In a large bowl, combine the ground beef, Worcestershire sauce, Montreal Steak Seasoning, and crushed garlic. Mix gently with your hands until just combined; be careful not to overwork the meat.
Divide the meat mixture into four equal portions, shaping each into a patty about ¾-inch thick. Make a slight indentation in the center of each patty to prevent them from puffing up while cooking.
Heat the same skillet over medium-high heat. Once hot, add the patties and cook for about 4-5 minutes on each side for medium doneness. In the last minute of cooking, place a slice of Swiss cheese on each patty and cover the skillet to help the cheese melt.
If you like your buns toasted, place them cut-side down on a baking sheet under the broiler for a minute or two until golden brown.
Place each cooked patty on a bun and top generously with caramelized onions. Add any additional toppings you prefer, then place the top bun on.
