Cucumber, crab & potato salad

Put the potatoes in a pan of salted water and bring to the boil. Reduce the heat and simmer for 15-20 minutes until easily pierced with the tip of a sharp knife. Drain well, cut into 2cm slices and return to the pan, off the heat; leave to cool.

Meanwhile, slice the cucumbers on a steep diagonal, about 0.25cm thick, to give long oval slices. Put in a large mixing bowl. Add the shallot, chilli, lemon juice and 1 tsp salt, then toss together. Set aside, giving it an occasional stir.

Once the potatoes have cooled, tip them into the cucumber bowl along with the lemon zest, chopped tarragon, remaining ½ tsp salt and the oil. Add ½ of the crabmeat and ½ of the watercress to the bowl, season and toss together. Divide between plates or shallow bowls and top with the remaining crab. Scatter with the remaining tarragon and watercress, then drizzle over a little more oil before serving.