Warm the oil in a large pan over medium heat (this can be done on a stovetop or in a dutch oven set over your hot embers of a campfire) and add the onion, red pepper, green pepper, carrots, garlic, and salt. Saute until soft, about 4 minutes.
Add the sweet potato and lime zest, and cook 10 to 15 minutes more, continuing to stir occasionally.
Add the jalapeno, cumin, chill powder, cinnamon, cocoa and oregano, stir and cook for a minute or two.
Add the tomatoes, black beans, lime juice and sugar. Bring to a simmer, cover, and cook for 20-40 minutes, until the sweet potatoes are very soft.