Watercress and Mandarin Orange Salad

I can't believe that I have never tried watercress.  So when I saw it in the market, I thought I should buy it.

Watercress and Mandarin Orange Salad

1/4 cup rice vinegar (not seasoned)
1 tablespoon grated sweet onion such as Vidalia or Walla Walla (use large holes of a box grater)
2 T finely grated peeled Gala apple (use small holes of box grater)
2 teaspoons soy sauce
1 teaspoon sugar
3 tablespoons vegetable oil
6 cups watercress (thin stems and leaves only; from 1 large bunch)
4 mandarin oranges, segmented

Stir together vinegar, onion, apple, soy sauce, and sugar until sugar has dissolved, then stir in oil.

Just before serving, toss watercress with enough dressing to coat. Arrange the mandarin segments around the watercress.

Notes:

·Watercress can be trimmed 1 day ahead and chilled in a sealed bag lined with damp paper towels.

·Dressing can be made 2 days ahead and chilled, covered. Stir or shake before using.