4 medium potatoes, yellow-fleshed are best
20 cm (7-8 in) finely sliced leek
1/4 peeled and chopped red or yellow onion (red is milder)
2 Tbsp mixed chopped green herbs, such as parsley, chives, basil, or thyme
1 Tbsp capers

Basic vinagrette

1 Tbsp water
1 Tbsp fine vinegar of your choice
1 Tbsp liquid sweetener of your choice
1 tsp Dijon mustard

1. Boil the potatoes whole with skin intact until just soft. Peel (if desired) and cut into pieces while they're still warm.

2. While the potatoes are cooking, put all the vinaigrette ingredients in a small prep bowl. Whisk with a small whisk or a fork, until the dressing emulsifies.

3. Mix the leek, the onion, the chopped herbs, the capers, and the vinaigrette in a bowl and let it marinate.

4. Put the warm potato pieces in a salad bowl. Pour the vinaigrette with the seasonings over the potato pieces and mix everything carefully. Let the salad marinate for at least 1 hour at room temperature before serving.