Rinse lentils and drain. In a Dutch oven combine lentils, water, carrots, onoins, celery, garlic, curry powder, ginger (or use 1/4 t ground ginger), and salt. Bring to boiling; reduce heat. Cover and simmer for 30 minutes or till lentils are tender. In a medium mixing bowl stir together yogurt, tomato, and parsley, if desired. Serve with lentil mixture. Per serving: 242 calories, 16 g protein, 43 g carbohydrates, 2 g fat, 4 mg cholesterol, 446 mg sodium, 811 mg potassium. Add crunch to the meal with toasted pita bread wedges.