1. Remove the outer stalks of the celery, leaving a heart about 1 inch wide and 6 inches long. Cut each celery heart in half lengthwise. Cut away all but the small leaves and trim the root ends (do not cut too deep; the celery halves should hold together). Use the cut-away leaves for the herb bouquet. With a sharp knife, scrape the outer stalks if they seem coarse.
2. Arrange the celery halves side by side in a 10- or 12-inch skillet, preferably enameled or stainless steel, and pour in the stock, using more stock or water if the celery is not completely covered. Add the herb bouquet, with as much salt and pepper as suits your taste, and bring to a boil.
3. Reduce the heat to its lowest point, cover tightly and simmer the celery for about 15 minutes, or until it shows no resistance when pierced with the tip of a sharp knife. With tongs or a slotted spoon, transfer the celery halves to a deep platter that will hold them in a single layer.
4. With a whisk, beat the vinegar and the oil together and pour over the celery while it is still warm. Refrigerate for at least an hour before serving. To serve, arrange the celery halves on individual chilled plates and crisscross 2 anchovy fillets and 2 strips of pimiento over each serving.
5. Or instead, if you prefer, garnish the celery with a slice of tomato and a slice of hard-cooked egg. In either case, moisten the celery with a spoonful or so of the vinegar-olive oil sauce and sprinkle with chopped parsley.
