Tender roasted fingerling potatoes pair harmoniously with wilted watercress in this simple salad. Be sure to toss the watercress and vinaigrette with the potatoes as soon as they come out of the oven so the cress wilts and the dressing penetrates the potatoes as they cool.
400g fingerling or small new potatoes, halved lengthwise
5 Tbs. extra-virgin olive oil
2 Tbs. white wine vinegar
1 tsp. Dijon mustard
1 medium bunch watercress (about 85g), stemmed
Freshly ground black pepper