Sweet Potato Soup from the yogurt lid

From the Dannon peel-off foil:
Dice large onion and saute with cumin, ground or whole. Add 3 peeled and cubed sweet potatoes. I'd microwaved mine to facilitate the peeling. Add 1 1/2 quart vegetable broth, bring to a boil and simmer for 25 min. Puree solids with 1 1/2 cups yogurt and return to pot to mix with broth. Add chopt parsley or cilantro. Recipe suggests adding a sprinkle of pumpkin seeds. I didn't have any, but something salty and crunchy could be nice.