1. Heat oil in a large pot over medium heat. Add onion and sauté three to five minutes, until softened.
2. Add lentils, carrot, tomato puree, cilantro, garlic powder and water, and bring to a boil. Reduce heat to low and simmer, covered, for 30 to 45 minutes, until lentils are tender.
3. Season with salt and pepper to taste and optional red pepper flakes. Garnish with additional cilantro.
When using prepared soup broth, look for organic, MSG- and BPA-free broth with less than 140 milligrams of sodium per serving.