Step 1

Take a blender and blend mayonnaise, 2 tablespoons relish, capers, 1 tablespoon chopped onion, parsley, and sugar.

Step 2

Blend them until they are completely smooth.

Step 3

Take the rest of the relish and onion. Stir both into the blended mixture.

Step 4

Transfer the sauce to the bowl and cover it with plastic wrap.

Step 5

Refrigerate it for at least 2 hours.