Smoky Black Bean and Sweet Potato Chili

Name: Smoky Black Bean and Sweet Potato Chili
Ingredients: 1 1/2 cups dried black beans; 4 cups sweet potato, diced into 3/4 inch cubes; 1 tablespoon olive oil; 2 cups chopped white or yellow onion (about one medium to large onion); 2 cloves garlic, minced; 1 chipotle pepper en adobo, chopped finely; 2 teaspoons cumin powder; 1/2 teaspoon smoked paprika; 1 tablespoon ground chili powder; 1 14 or 15 ounce can of diced tomatoes; 2 cups vegetable broth (and more as needed); sea salt to taste; 1/4 cup chives, snipped into small pieces; 1 large Haas avocado