Start by gathering all your ingredients. This will make the preparation process smooth and efficient.
In a mixing bowl, combine the 3/4 cup of mayonnaise with the 1/4 cup of crème fraîche (or sour cream). Stir until well blended.
Fold in the 1/4 cup of finely chopped dill pickles (or cornichons) along with the 2 tablespoons of capers to add crunch and brininess.
Add the finely minced shallot and garlic to the bowl to provide savory depth.
Toss in the tablespoon of chopped fresh parsley (or dill) and the 2 teaspoons of fresh lemon juice for a burst of freshness.
Season the mixture with 1 teaspoon Dijon mustard, 1/4 teaspoon onion powder, 1/4 teaspoon freshly ground black pepper, and, if desired, the hot pepper sauce. Taste and adjust seasoning.
Optionally, fold in the finely chopped olives and horseradish to add extra flavor complexity.
Cover the bowl with plastic wrap and refrigerate for at least 30 minutes to allow flavors to meld. Serve alongside fried fish, seafood, or as a vegetable dip.