Start by collecting all your ingredients. This ensures that you have everything you need and makes the process smoother.
Using a sharp knife, finely dice the dill pickles, bread-and-butter pickles, and peeled yellow onion. Aim for small, uniform pieces to blend seamlessly into the sauce.
In a large mixing bowl, add the mayonnaise, distilled white vinegar, Dijon mustard, and sugar. If you like a touch of sweetness, now is the time to add your optional ketchup.
Fold in the diced dill pickles, bread-and-butter pickles, and yellow onion into the mayonnaise mixture. Stir gently until all ingredients are well combined.
Add coarse salt and freshly cracked pepper to taste. Remember, you can always adjust the seasoning later, so start with a little and increase it gradually.
For the best flavor, cover the bowl with plastic wrap and refrigerate the sauce for at least 30 minutes. This allows the flavors to meld beautifully. Serve it up with your favorite burgers and enjoy!