Spinach-Clementine Salad

6 cups baby spinach leaves12 clementines, sectioned 1/2 cup walnut or pecan pieces1 bunch green onions, sliced crosswise (optional) 1/2 cup sliced water chestnuts (optional)Dressing3 tablespoons olive oil 1/4 cup fresh lemon or lime juice1 tablespoon Dijon mustard (optional)Place the salad ingredients in a large bowl.In a small bowl, stir together olive oil, lemon juice and mustard, if using. Toss dressing with salad and serve.Serves four to six.Nutrition values per serving: 216 calories, 14 g fat (1.5 g saturated), 24 g carbohydrates, 5 g fiber, 3 g protein, 0 cholesterol, 73 mg sodium.Dr. Gabe Mirkin