Using a scale, weigh out approximately 4 oz of 80/20 Lean Ground Beef (24 ounce) for each burger patty and press them out on wax paper.
Dice your Sweet Onion (1) and saute in oil over high heat to get a nice color, then drop the heat to medium and let them cook down for at least 20 minutes or more adding water periodically to the pan for moisture and to deglaze any onion crumbles.
Season your six burger patties with Salt (1/4 teaspoon) and Freshly Ground Black Pepper (1/8 teaspoon).
Place the patties on a hot grill or stove pan, add Yellow Mustard (to taste).
We decided to layer our burger with Iceberg Lettuce (1 head) first as a barrier to all the grease. Then a layer of Tomato (1), sliced Dill Pickle (to taste), American Cheese Slice (6 slice) and all six mustard grilled cheeseburgers.
Make Animal Style spread by mixing Mayonnaise (1/2 cup), Ketchup (1/4 cup), Sweet Pickle Relish (1/4 cup), Granulated Sugar (1/4 teaspoon), Salt (1/4 teaspoon), Freshly Ground Black Pepper (1/8 teaspoon), Lemon Juice (1/8 teaspoon). Spread onto burger and top with chopped Chili Pepper (to taste).