In saucepan, combine lentils and 6 cups water anc cook over med. low heat for 15 minutes, or until lentils have softened. In large saucepan over med heat saute the onion in olive oil for 5 min. Stir in garlic and criander and mix well. Add spinach and cook for 1 min or until wilted. Add spinach/garlic mixture and salt to lentils. Simmer for about 10 minutes or until soup has a thick consistency. Sprinkle pepper flakes and mix.
