In a medium bowl, whisk together the mayonnaise, dill pickle, ketchup, onion, sweetener, oil, vinegar, paprika, mustard, salt, and pepper. Refrigerate until ready to serve.

Heat a skillet over medium-high heat. Add the ground beef and season to taste with salt and pepper. Cook, breaking it up with the back of a spoon until browned. Remove the meat from the skillet with a slotted spoon and transfer it to a paper towel-lined plate.

Combine the lettuce, cheese, and red onion in a large bowl. Toss with half of the dressing. Top with the meat and dill pickles and drizzle with the remaining sauce.