2 large onions finely chopped
salt
1/4 C mayo
2 Tbsp ketchup
1 Tbsp sweet pickle relish
1/2 tsp white vinegar
1 1/2 tsp mustard
2 lbs. ground chuck 60%
4 hamburger buns
pickles
1 C shredded iceberg lettuce
4-8 slices tomato
pepper
8 slices American cheese I used cheddar
Heat oil in pan and add onions. Cook onions covered, over medium heat for 30 minutes or until onions begin to turn golden brown and caramelize. Watch them so they don't burn. Remove lid and cook for 5 more minutes and then add 1/2 C water. Allow water to evaporate. Set aside, onions can be made several days ahead of time and refrigerated. Mix together the mayo, ketchup, relish and vinegar in a bowl and set aside. Form meat into 8 patties about 4 inches wide and 1/2 inch thick. Heat griddle and lightly brush with vegetable oil. Toast the buns on the griddle, split side down. After they are toasted golden brown spread the bottom bun with 1 Tbsp of the mayo mixture. Top with tomato and lettuce. Salt and pepper both sides of hamburger patties and cook on the griddle for 3-5 minutes. Spread top of patty with 1 1/2 tsps mustard and flip. Top patty with cheese and allow to cook until desired doneness. Add hamburger to bun and top with caramelized onion.