In a large pot, heat oil. Saute peppers, onions, and salt until softened.
Add chili powder, smoked paprika, and garlic. Stir and cook for 1 minute or until fragrant.
Add beans, tomatoes, tomato sauce, broth, lentils, and cinnamon to the pot. Stir.
Bring to a simmer. Cover and continue to simmer for 30-40 minutes, or until lentils are tender.