supermarket, or near the mustards and pickles For a slightly sweeter sauce, substitute tablespoons prepared sweet pickle relish for the cornichons MAKES ABOUT 1 CUP ¾ cup mayonnaise, preferably homemade (here) 1 medium shallot, finely minced (about 2 tablespoons) 3 tablespoons capers, drained, patted dry, and finely minced 6 to 8 cornichons, finely minced (about 2 tablespoons; see Note above) 1 teaspoon sugar 2 tablespoons finely minced fresh parsley ½ teaspoon freshly ground black pepper Kosher salt Combine the mayonnaise, shallot, capers, cornichons, sugar, parsley, and pepper in a small bowl Season to taste with salt Transfer to an airtight container and refrigerate for at least 1 hour before using Tartar sauce will keep for up to 1 week in the refrigerator FRIED FISH SANDWICHES WITH CREAMY SLAW AND TARTAR SAUCE NOTE: This recipe will also work for any flaky white fish, such as haddock, pollock, or even halibut or striped bass