05Heat the canola oil a large heavy-bottomed skillet over medium-high heat.06In a small bowl combine the salt, pepper and garlic powder and season the burgers generously with the mixture. Put the patties in the skillet and cook for 4 minutes. Flip and let cook for 1 minute, then top each patty with a piece of cheese. Cook for another 2 minutes until the cheese is melted and the burgers are medium.07While the burgers are cooking, lightly brush the buns with melted butter and put them on a sheet pan. Broil until lightly toasted, about 2 minutes.08To assemble, split the buns and spread each half with about a tablespoon of the special sauce. Put the burgers on the bottom half of each bun, top with caramelized onions, tomato and lettuce. Cover with the top half of the bun and serve.