 It is most often used as a condiment with seafood dishes such as clam strips, fried oysters, fish and chips, fish sandwiches, and fish fingers, among many other dishes.Tartar sauce is based on either mayonnaise (egg yolk, mustard or vinegar, bitartrate, oil) or aioli (olive oil, garlic), with certain other ingredients added.In the UK, recipes typically add to the base capers, gherkins, lemon juice, and dill.