Don't skimp on the napkins at dinner because this is a juicy burger recipe! The caramelized onions and not so secret sauce are optional, but the mustard-seared patty is key to locking in those juices.
2 tablespoons vegetable oil
2 large yellow onions, finely chopped
coarse kosher salt
1/4 cup mayo
2 tablespoon ketchup
1 tablespoon dill pickle relish
1/2 teaspoon distilled white vinegar
1 pound 80/20 ground beef, formed into 4 patties and seasoned on both sides with kosher salt and black pepper
1/4 cup yellow mustard
4 slices American Cheese slices
4 hamburger buns, split
1 tomato, sliced thin
8 slices of dill pickle
4 large leaves of iceberg lettuce
1-2 heaping tablespoons not so secret sauce
1-2 tablespoons caramelized onions
To make the onions:
In a large skillet with a lid, heat the vegetable oil over medium-low heat. Add the onions and 3/4 teaspoon salt. Stir to combine, cover and cook, stirring occasionally for 30 min. If browning too quickly reduce heat.
Uncover, increase heat to med-high & cook, stirring often until caramelized, 7 min. Add 1/2 cup water to the pan, scraping up any browned bits on the bottom. Cook until the water has evaporated, about 2 more minutes. Set aside.
Can be made up to 3 days in advance and stored in the fridge.
Combine the mayo, ketchup, relish, & vinegar. Stir to combine. Set aside.
Heat a grill pan or heavy bottomed skillet over a medium-high heat or heat a grill to medium high. Lightly brush the grill or pan with vegetable oil. Toast the buns, split side down.
Add the seasoned patties to the griddle and cook for 4 minutes. Spread 1 –2 teaspoons mustard over the uncooked side of each patty then flip and cook for 2 minutes more. Top each burger with a slice of cheese and close the grill for a few minutes to allow the cheese time to melt. Renove from the heat and rest for a few minutes.
Spread the not so secret sauce on the toasted bun. Lay down the lettuce and place a patty on top. Add a scoop of caramelized onions, a slice of tomato, 2 slices of pickle, and another tablespoon or so of sauce. Serve immediately.