Mozzarella, plum and burnt leek salad

Method

1. Put the vinegar and sugar in a small saucepan over a medium heat. Warm through until the sugar has dissolved, then remove from the heat. Meanwhile, cut each plum in half and remove the stones. Put the plum halves cut-side down in the pickling liquid, then set aside for at least 30 minutes to lightly pickle, giving them the occasional stir.
2. Heat a grill to its highest setting. Put the leeks on an oven tray, drizzle with olive oil and season. Grill, turning occasionally, until blackened all over (about 10 minutes). When cool enough to handle, trim the ends and peel away the burnt outer layer of the leeks. Slice the soft insides into bite-size pieces.
3. Toss the watercress with a drizzle of olive oil and a splash of pickling liquid, then season to taste. Arrange the plums, leeks, watercress and mozzarella on a platter, then scatter with the hazelnuts. Finish with a grind of black pepper and an extra drizzle of oil and pickling liquid.