1 c. mayonnaise
1 tbsp. Dijon mustard
1 tbsp. white-wine vinegar
1 tsp. celery seed
4 c. washed, unpeeled, cooked small red potatoes, cut into chunks
1 c. sliced celery
1 c. watercress sprigs
Freshly ground pepper

In a large bowl combine mayonnaise, mustard, vinegar, and celery seed. Stir until well-blended. Add potatoes and celery; toss to coat well. Cover and refrigerate at least 1 hour. Just before serving, add watercress sprigs and toss lightly. Top with a little freshly ground pepper.