Soak the black beans in water for 6 to 8 hours, or overnight. Drain the soak liquid. Submerge them in fresh water, with enough to cover them by a few inches. Bring beans to a boil and lower to a simmer. Cook till beans are tender, approximately 45 minutes to one hour. Drain and set them aside.
Heat the tablespoon of oil in a dutch oven or a large pot. Saute the onion for a few minutes, then add the sweet potato and garlic. Keep sauteing until the onions are translucent, about 8-10 minutes.
Add the chili en adobo, the cumin, the chili powder, and the smoked paprika. Heat until the spices are very fragrant. Add the can of tomatoes and one can of vegetable broth.
When broth is bubbling, reduce to a simmer and cook for approximately 30 or 35 minutes, or until the sweet potatoes are totally tender. As you co along, you can continue to add the remaining cup of vegetable broth as is needed and depending on the texture chili you like. Season to taste with salt.
When chili is finished, allow it to sit for a little while so that flavors can marinate. To serve, top a generous bowl with some fresh avocado slices and chives.
Gena is a registered dietitian, recipe developer, and food blogger. She's the author of three cookbooks, including Power Plates (2017) and Food52 Vegan (2015). She enjoys cooking vegetables, making bread, and challenging herself with vegan baking projects.