With a small, sharp knife, cut ends off oranges. Set 1 orange, cut side down, on a cutting board. Following its curve with the knife, slice off peel and white pith.
Cut between inner membranes and fruit to release segments; drop segments into bowl. Repeat with remaining oranges.
Rinse and dry watercress. In a large bowl, toss watercress, Belgian endive, and oranges with just enough vinaigrette to coat. Divide among 12 salad plates and garnish each salad with pomegranate seeds and toasted almonds.
