Make the special sauce: In a small bowl, whisk 1/2 cup mayo, 2 tablespoons sugar-free ketchup, 1 tablespoon dill relish, 1 teaspoon yellow mustard, 1 teaspoon apple cider vinegar, 1/2 teaspoon onion powder, and 1/2 teaspoon paprika. Add a tiny pinch of keto-friendly sweetener if you like.
Season with salt and pepper. Chill while you cook the beef.
Prep the veg: Chop lettuce, dice tomato (if using), and chop pickles. Set aside.
Toast 1 teaspoon sesame seeds in a dry skillet over low heat for 2–3 minutes if you want extra flavor.
Cook the beef: Warm a large skillet over medium-high heat with a drizzle of olive oil or ghee. Add 1 pound ground beef and break it up with a spatula. Season with 1 teaspoon salt, 1/2 teaspoon pepper, 1/2 teaspoon smoked paprika, and 1/2 teaspoon onion powder.
Stir in 1/4 cup finely diced onion and 1 clove minced garlic (optional). Cook until browned with a few crispy bits, about 6–8 minutes. Drain excess grease if needed.
Melt the cheese: Lower the heat.
Sprinkle shredded cheddar or lay chopped American slices over the hot beef. Cover for 1 minute to melt, or mix in until gooey.
Assemble the bowls: Add a generous bed of chopped lettuce to each bowl. Spoon on a portion of the cheesy beef.
Top with chopped pickles, tomato, and avocado slices if using. Drizzle with special sauce.
Finish and serve: Sprinkle with toasted sesame seeds. Add extra sauce on the side for dipping.
Taste and adjust salt or acidity as needed.