Divide the ground beef into equal portions and shape them into thin patties, slightly larger than the final size to account for shrinkage during cooking.

Season both sides of each patty evenly with salt and black pepper to enhance flavor.

Heat a pan over medium-high heat and place the patties onto the hot surface, cooking for 3–4 minutes per side until browned and cooked

During the last minute of cooking, place a slice of cheddar cheese on top of each patty and allow it to melt gently. You can loosely cover the pan for a few seconds to help the cheese melt faster without overcooking the meat.

While the patties are finishing, prepare the sauce by combining mayonnaise, sugar-free ketchup, mustard, and pickle juice in a small bowl. Stir well until the mixture is smooth and creamy, making sure all ingredients are fully blended.

Remove the cooked patties from the pan and let them rest for a minute. This helps retain their juices and keeps the burgers moist and flavorful when assembled.

Lay out the lettuce leaves on a clean surface, choosing the largest and most intact pieces so they can hold the fillings properly without tearing.

Place each cheesy patty onto a lettuce leaf, then add sliced onions and pickle slices evenly on top to build layers of flavor and texture.

Spoon a generous amount of the prepared sauce over each burger, letting it slightly drip over the sides for that classic, messy, fast-food-style feel.

Gently fold or wrap the lettuce around the burger to hold everything together, or leave it open-faced if you prefer a lighter presentation.

Serve immediately while warm, optionally adding an extra drizzle of sauce on top or on the side for dipping.