Instructions

1. Brush the chicken breast with olive oil, season with salt & pepper then grill it or and fry it in a griddle pan. Let it rest then cut it into chunks.
2. If you're using leftover chicken, shred it into bite-size chunks.
3. Dry-fry the walnuts (i.e. without any oil) until golden and aromatic.
4. Cut the grapes in half; the apple into small cubes; the celery stalks into thin slices.
5. Mix the vegetables, chicken chunks and toasted walnuts in a serving dish.
6. Whisk the yogurt, lemon juice and mustard in a small bowl. Season to taste then add it to the salad. Mix well.
7. Taste it and adjust the seasoning, lemon juice or mustard.
8. Just before serving, add the chopped watercress leaves or sprinkle with chopped parsley.