In a large pot over medium-high heat, heat the oil. Add onion and saute for 2 minutes, until the onion is translucent and tender. Add the garlic and curry powder and saute for another 2 minutes.
Add the sweet potatoes and cook for 2 more minutes.
Add tomatoes, veggie broth, and cayenne pepper. Cover, bring to a boil, and lower to a simmer for 20 minutes.
Add peanut butter and coconut milk to the pot. Cover and let simmer for 30 minutes.
