  ¼ cup extra-virgin olive oil  0 tablespoons freshly squeezed lemon juice  0 tablespoon imported French mustard  0 small spring onions or scallions, white part only, trimmed, peeled, and thinly sliced  ¼ cup Capers in Vinegar (see Capers in Vinegar), drained  Fine sea salt  ¼ cup fresh mint leaves, cut into a chiffonade  0. Scrub the potatoes but do not peel them. Bring 