Serves 4

3 Portabello mushrooms, thinly sliced
1 medium apple, cut into chunks and coated with lemon juice
2 celery sticks, cut into matchsticks
1/4-cup walnut pieces
1 bunch watercress

Dressing
1 tbsp mayonnaise
1 tbsp thick yogurt
1/2 tsp herb flavoured mustard
a little lemon juice
salt & pepper

Method
Place the mushrooms, apple, celery and walnuts in a bowl. Combine all the ingredients for the dressing and mix gently with the vegetables. Arrange the watercress on a flat dish or platter and mound the salad mixture on the top.
Variation: A medium bulb of fennel, finely sliced, could be used in place of the celery.