Serves 12 Ingredients For the Pickled Pearl Onions 1¼ pounds pearl onions 3 tablespoons sugar 8 cloves 1 teaspoon yellow mustard seeds Eight ½-wide strips of lemon zest 1¼ cups white vinegar 1¼ cups water 2 teaspoons kosher salt For the Wood Sorrel Ash 2 ounces wood sorrel For the Celery Root Purée 1 medium…