Salad of mache, walnuts and black truffles

This is the simplest possible salad, using walnuts found in the market and sweet delicate mache – otherwise known as lamb's lettuce – from the garden. It would make an elegant first course.

Serves 4

20 fresh walnuts
100g/31/2oz mache (lamb's lettuce)

For the vinaigrette

1tsp Dijon mustard
2tbsp red-wine vinegar
100ml/31/2fl oz walnut oil (or, if you're using truffle oil rather than truffles, use it here instead of walnut oil)

To serve

Sea salt and freshly ground black pepper
A few shavings of black truffle

Using a nut cracker, remove the walnuts from their shells. Wash the lettuce well and pat dry. To make the vinaigrette, place the mustard in a bowl and add a pinch of salt and pepper, then add the vinegar and stir well to combine. Slowly whisk in the oil so it forms a thick emulsified sauce.

Place the lettuce in a bowl and add the walnuts, season with a little salt and pepper and spoon over the dressing. Arrange the salad attractively on a flat plate and shave over a little truffle.