Remove tough dark green tops of leeks. Thinly slice the white and light green portions. Thoroughly rinse and drain sliced leeks in a colander. In Dutch oven or large saucepan, heat olive oil on med. Add leeks and garlic and cook until leeks are tender, about 5 minutes. Add drained and rinsed chickpeas and cook 1 minute. Add the chicken broth (or vegetable broth if you wish to make it vegetarian). Simmer for 15 minutes. Remove half of the soup and using an immersion blender, food processor or blender, puree. Retun pureed soup to pan and mix well. Season with salt and pepper. Top each serving with 1 tbsp of grated parmesan cheese. Makes 8 servings.