
This smoked mackerel and new potato salad is light, satisfying, and full of bold flavor. Tender potatoes, crisp green beans, peppery watercress, and flaky smoked fish are tossed in a sharp mustard-dill dressing for an easy lunch or dinner.
Bring a pan of well-salted water to the boil. Cook the new potatoes for 12-15 minutes, or until just tender when pierced with a knife. Add the green beans during the last 3 minutes of cooking. Drain well and leave everything to steam-dry for 5 minutes.
While the vegetables are cooking, make the dressing by stirring together the finely chopped shallot, red wine vinegar, olive oil, Dijon mustard, chopped dill, and sliced cornichons. Season to taste with salt and black pepper.
When the potatoes are cool enough to handle, halve them. Gently toss the warm potatoes and green beans with the dressing, then fold in the watercress and flaked smoked mackerel.
Divide the salad between two plates and spoon over any dressing left in the bowl. Serve immediately while the potatoes are still slightly warm.
If you cannot find hot smoked mackerel, smoked trout works well too. Avoid overmixing once the fish is added so the fillets stay in nice flakes. Leftovers can be chilled in an airtight container for up to 1 day, though the watercress is best when freshly dressed.