Pulse the 5 oz. pickled vegetables (such as dill pickles, cornichons, cocktail onions, peperoncini, capers, jalapeños, and/or hot cherry peppers)
Add the dill, buttermilk, shallot, garlic, lemon juice, salt, and pepper and pulse several times.
Add the sour cream and pulse a few times to combine.
Taste the dressing and season with more salt if needed. Cover and chill for at least 1 hour.
Epicurius adds 1/2 tsp of sugar and I think I would only add sugar if I was using something hot like pickled jalapeños or something bitter.