Ingredients

3/4 pound small waxy potatoes, such as fingerling or new potatoes

1 small shallot, very thinly sliced

4 teaspoons white-wine vinegar

2 teaspoons Dijon mustard

4 teaspoons olive oil

2 tablespoons roughly chopped fresh dill

1/2 cucumber, peeled, halved lengthwise, and sliced into 1/2-inch semicircles

Freshly ground pepper

12 ounces smoked mackerel, broken into bite-size pieces

Handful of tender salad greens, such as arugula, watercress, or tatsoi

Preparation

Place potatoes in a small saucepan, and cover with cold water. Bring to a boil; reduce heat, and simmer until tender when pierced with a fork, about 12 minutes. Drain in a colander; let cool slightly. Slip off skins; discard. Cut potatoes into halves or quarters, if desired.

Meanwhile, make dressing: In a medium bowl, combine shallot, vinegar, and mustard. Whisk in the oil until emulsified. Sprinkle dill into bowl.

Add cucumber and cooked potatoes to the dressing in the bowl; season with pepper. Toss to coat evenly. Divide salad among four plates; arrange mackerel on each. Serve, garnished with greens.