Watermelon Goat Cheese Salad with Citrus Vinaigrette

Name: Watermelon & Goat Cheese Salad with Citrus Vinaigrette
Ingredients: 3 tablespoons extra-virgin olive oil; 3 tablespoons orange juice; 1 tablespoon red-wine vinegar; ¼ teaspoon salt; Freshly ground pepper, to taste; 8 cups watercress, tough stems removed, or mixed salad greens (5 ounces); 4 cups diced seedless watermelon, (about 3 pounds with the rind) (see Tips); 2 ounces goat cheese, crumbled; 1/4 cup very thinly sliced red onion, (1/4 small); 1/2 cup chopped hazelnuts, (2 ounces), toasted (see Tips)