Step 1

For the dressing, whisk all the ingredients in a bowl until smooth, then season with sea salt and freshly ground pepper to taste. Add 1-2 tablespoons of water, a spoonful at a time, whisking until light and creamy. Set aside.

Step 2

Take the chicken meat off the bones and cut into bite-size chunks. Toss the chicken, potato, cucumber and chives in the dressing.

Step 3

Divide the lettuce and salad among serving bowls. Sprinkle with nigella seeds, garnish with extra chives and serve with lemon wedges.