Succulent Grass-Fed Beef Burger

Instructions:

1. In a small bowl, combine ketchup, 1/4 cup of mayonnaise, vinegar and Worcestershire sauce. Season with salt and pepper.
2. Heat oil in a skillet over medium high heat. Saute onions for 2 minutes and reduce the heat to medium, cooking the onions until soft and carmelized (about 5 minutes), stirring often. Cool.
3. Combine carmelized onions, 2 TB mayonnaise, garlic powder, pepper and ground beef in a bowl, stirring until just mixed. Shape the mixture into 4 (1/4 inch) patties.
4. Heat a grill pan over high heat and coat with cooking spray. Add patties, cook 3 minutes, turn patties and add the cheese slices. Cook another 2 minutes until desired doneness.
5. Toast the hamburger buns.
6. Spread the ketchup mixture on top half of the buns. On the bottom of the buns add the patty, tomato slices, lettuce and pickles. Cover with top halves of the buns.