1Heat butter in pot over medium heat; cook and stir onion, sweet potato, red bell pepper, celery, zucchini, jalapeno pepper, and garlic in the melted butter until vegetables are softened, about 10 minutes.
2Stir vegetable stock, quinoa, cumin, oregano, salt, black pepper, and cayenne pepper into vegetable mixture; bring to a boil. Reduce heat, cover pot, and simmer soup until quinoa is tender, 10 to 15 minutes. Stir peanut butter into soup and simmer until flavors have blended, about 20 more minutes.