2 pounds large Yukon Gold potatoes, or other waxy, boiling potatoes
2 tablespoons cider vinegar
1/3 cup chicken stock or potato-cooking water
2/3 cup finely chopped onion
1/2 cup finely chopped celery
3 or 4 slices crisply cooked bacon, chopped or crumbled
2 to 3 Tbs finely chopped pickle, sweet or dill
2 hard-boiled eggs, peeled and sliced thin
3 Tbs or so finely chopped fresh chives or scallions, including a bit of their tender green
Salt and freshly ground white pepper
1 cup or so mayonnaise, homemade if possible
Sour cream, optional
Crisp whole red-leaf or other lettuce leaves
Canned red pimiento, diced
Sliced hard-boiled eggs
Tomato quarters
Parsley sprigs