Step 1

Prepare the following, adding them to a small bowl as you complete them: Finely chop 1 small shallot (about 2 tablespoons). Finely grate the zest of 1 small lemon until you have 1 teaspoon zest. Juice the lemon until you have 1 tablespoon juice. Stir to combine and let sit for a few minutes so the lemon juice mellows the shallot.

Step 2

Prepare the following, adding them to the bowl of lemon and shallots as you complete them: Chop 9 cornichons or 2 baby dill pickles into small dice (about 1/3 cup). Place 2 tablespoons capers in a fine-mesh strainer and rinse under cold water, then pat dry and coarsely chop. Finely chop 2 tablespoons fresh parsley leaves and 1 tablespoon fresh tarragon leaves.

Step 3

Add 1 cup mayonnaise, 1 teaspoon cornichon or pickle brine, 1/4 teaspoon kosher salt, and 1/4 teaspoon black pepper, and stir to combine.