Sweet Potato Chili With Goji Berries

Name: Sweet Potato Chili With Goji Berries
Ingredients: 1 tablespoon extra-virgin olive oil; 1 large yellow onion, chopped; 1 large red bell pepper, diced; 6 garlic cloves, chopped; 2 tablespoons tomato paste; 28 ounces tomato puree; 1 large sweet potato, peeled and diced; 1 canned chipotle pepper in adobe, finely minced; 1/4 cup goji berries; 15 ounces cooked (canned) pinto beans, rinsed and drained; 2-1/2 cups vegetable broth; sea salt and black pepper, to taste; 1 teaspoon balsamic vinegar; 2 teaspoons ground cumin; 1 teaspoon ground turmeric; 1 tablespoon chili powder; yogurt, to top (optional)