2. Heat the oil in a large soup pot. Add the onion and garlic and sauté over medium heat until golden. Add the bell pepper, beans, tomatoes, chilies, cumin, and oregano. Bring to a simmer. Cover and simmer gently for 15 minutes. Add the sweet potatoes and continue to simmer until the vegetables are tender -- about 10 to 15 minutes.

3. Season lightly with salt. If time allows, let stand off the heat for 1 or 2 hours, then heat through as needed.

Embellish it:
Pass a bowl of chopped fresh cilantro for sprinkling over the top of individual portions.