In a heavy bottomed pot, heat the oil and chopped onion over medium heat until softened, about 5 minutes.

Add the sweet potatoes and broth, bring to a boil. Once boiling, reduce heat to medium low and cook for about 20 minutes.

Add the quinoa, cup of water, and spices and continue cooking until quinoa is tender (you will see the little ring around the edge of the quinoa loosen), about 15 more minutes. If too much of the water has evaporated, add a bit more. It should be a thick soup, but you should still see broth.

Add the corn and cook until corn is heated through, about five minutes.

Serve topped with cilantro if desired.