- 2 tablespoons olive oil
 - 1 1/2 cups chopped onion
 - 1 cup chopped celery
 - 1 cup chopped peeled carrots
 - 3 garlic cloves, minced
 - 1 tablespoon curry powder (preferably Madras-style)
 - 1 tablespoon minced fresh ginger
 - 1 teaspoon ground cumin
 - 1 bay leaf
 - 1/4 teaspoon dried crushed red pepper
 - 9 1/2 cups (or more) water
 - 1 16-ounce bag dried lentils (about 2 1/2 cups)
 - 1 6-ounce bag baby spinach leaves
 - 1/2 cup chopped fresh cilantro
 - 1/2 cup plain nonfat yogurt
 
- Heat oil in heavy large pot over medium-high heat. Add next 4 ingredients; sauté until golden, about 10 minutes. Stir in curry powder, ginger, cumin, bay leaf, and dried crushed red pepper. Add 9 1/2 cups water and dried lentils; bring to boil. Reduce heat to medium-low and simmer uncovered until lentils are tender, adding more water by 1/2 cupfuls to thin soup, if desired, about 25 minutes. Add spinach and cilantro; simmer until spinach is wilted, about 5 minutes. Season soup with salt and pepper. (Can be made 1 day ahead. Chill soup uncovered until cold, then cover and keep refrigerated. Rewarm soup over medium heat, thinning with water if desired before serving.)
 - Ladle soup into bowls. Top each serving with spoonful of yogurt.