FOR THE SAUCE: In a medium bowl, stir together the mayonnaise, pickles, mustard, vinegar, onion, and sweetener. Set aside.
FOR THE SALAD: Heat a large skillet over medium heat. Add the ground beef and cook, breaking it up with a wooden spoon. Cook about 5 minutes, stirring frequently. Add the salt and pepper and cook until no longer pink, about 2 minutes.
In a large bowl, combine the lettuce, onion, cheese, and pickles. Divide the lettuce mixture evenly among four bowls. Top each with one-quarter of the ground beef mixture. Drizzle with the dressing.
This would make a fantastic leftover salad as long as you don’t mix everything together. Divide the ingredients evenly in four mason jars, layering in the following order: lettuce, cheese, diced pickles, and sauce. Put the ground beef into four smaller microwaveable containers. Heat the beef, add to jar, and shake the concoction like your life depended on it. Voila! Salad!
The sauce will keep for at least a week in the fridge so make a double batch. Great for dipping grilled chicken as well.