Preheat oven to 400F.
Arrange and assemble all of the ingredients.
Make the spread. Mix spread ingredients together in a small bowl. Set aside.
Form beef patty(s), pressing 4 ounces of beef flat to 4-inches in diameter for a single patty. Sprinkle both sides with salt and freshly ground pepper. This is the only place you will be using salt and pepper, so let your personal taste be your guide.
Heat griddle or heavy skillet over medium-high heat. Add 2 teaspoons olive oil. Sear patties on one side. Squirt some mustard on them as they cook. After just 2 or so minutes, flip the patties over so the mustard cooks into the second side (yes, you are frying the mustard). Cover each beef patty with a slice of cheese. After a couple of minutes or when internal temperature as reached 145 F on an instant-read thermometer, remove to a plate and cover loosely with foil. While patties are frying, place closed bun in the hot oven for exactly 2 minutes.
To caramelize the onion (if you choose, rather than placing raw onion on your cheeseburger), chop finely and then allow to cook in the meat juices that have formed. Turn onion often so it becomes brown and caramelized, but not burned.
Open the bun and place it on griddle or skillet so it “toasts” in some of the meat juices. Watch carefully so it gets nice and brown, but does not burn.
Spread 2 tablespoons of the spread on the bottom, toasted bun. Top with four dill pickle slices. Next, comes a slice of tomato and lettuce. Lay one of the cheesed-up and mustard-fried beef patties on top of the lettuce followed by the raw onion slice or grilled onions, the second cheesy beef patty, and then the top bun. By now you are noticing a lot of moisture aka sauce and drippings, which explains why INO wraps each burger in parchment paper. That's it! A Double-Double Cheeseburger, INO style.
To make a Single Cheeseburger, use only one beef patty and one slice of cheese.