This potato soup is accented with cumin and cayenne, and the added lentils make it a well-rounded pareve [vegan] meal.
In large saucepan, heat oil over medium heat; cook onion, potatoes, celery, lentils, garlic, thyme, salt, pepper, cumin and cayenne pepper, stirring often, until onion is softened, about 5 minutes. Add stock; bring to boil. Reduce heat to low; simmer until potatoes and lentils are tender, about 30 minutes. Serve sprinkled with parsley.