1 pound small to medium-size red of Chioggia beets (with 1 inch of stems left intact)
  olive oil
3 navel oranges
2 tablespoons raspberry vinegar
2 tablespoons chopped shallots
1 teaspoon Dijon mustard
1/3 cup extra-virgin olive oil
1 tablespoon fresh thyme leaves
1/2 teaspoon salt
  freshly ground pepper (to taste)
4 cups watercress leaves (washed and dried)