2 pounds new potatoes
10 ounces, plus more to taste, plain yogurt (not Greek)
3 to 4 tablespoons olive oil
1 tablespoon, or more, of prepared ground horseradish
4 scallions, thinly sliced (white and pale green parts)
Coarse sea salt and freshly ground black pepper
A small box of garden cress
Wash the potatoes, but don’t peel them. Put them in a pan with salted water to cover, cover, bring to a boil and simmer for 25 to 30 minutes, until tender. Drain well, transfer to a large serving bowl and, while they are still hot, crush them roughly with a fork.
In a small bowl, mix the yogurt, olive oil, horseradish, scallions, salt and pepper to taste. Pour this dressing over the hot potatoes and mix well. Adjust the seasoning, adding more horseradish or more salt. You want the dressing to be assertive – the potatoes will mellow it out. Just before serving, snip in the garden cress and mix once more.