Long John Silver's serves fried fish and shrimp and other seafood delicacies. Tartar sauce is made using mayonnaise, diced pickles, and other ingredients. Especially with fried fish, it's a condiment.
To start, combine the mayonnaise, diced pickles, onions, dill pickles, lemon juice, dill, salt, and pepper in a medium-sized bowl.
Stir everything together until it's well combined.
You can also use a blender or food processor to mix everything together if you want a smoother, more homogenous sauce.
Notes
Taste and season your tartar sauce after mixing. Add lemon juice or sliced pickles for extra tang. Add salt or black pepper to make it tastier.
When your tartar sauce tastes good, put it in a sealable jar and refrigerate it until used. It lasts a week in the fridge, so make a batch at the start of the week and use it on all your fish dishes.