No mayo in this tangy, slightly spicy version of the summer classic. The yellow potatoes absorb the flavors better than red ones but stay firm and creamy. I often add parboiled green beans to it.
Wash 1 lb. of potatoes. Bring a pot of salted water to a boil and add the potatoes. Cook at a low boil for 10-15 minutes (smaller spuds will cook more quickly).
Thinly slice red onion to make 1/3 C. Marinate in 1 T. red wine vinegar or lemon juice for 10 minutes.
Test the potatoes with a sharp knife for tenderness. When the knife pierces easily into the middle of the potato, it is done. Remove the potatoes and rinse with cold water. Allow to cool for 10 minutes or so.
Add 1 T. stoneground or Dijon mustard and 2 T. olive oil to the onion/vinegar mixture. Press 1 small clove of garlic in a garlic press and add to the dressing.
Chop Greek-style pitted green olives to make 2 T. and add to the dressing.
Dice the potatoes and add to the dressing. Toss to coat, then taste and add salt and pepper to taste.