Heat the olive oil in a large pot over medium heat. Add the chopped onion and cook for about 5 minutes, until it becomes translucent.
Stir in the minced garlic and chopped red bell pepper. Sauté for another 3-4 minutes until the pepper softens.
Add the diced sweet potatoes to the pot and stir well. Cook for about 5 minutes, allowing the sweet potatoes to begin to soften.
Sprinkle the chili powder, cumin, smoked paprika, and cayenne pepper over the vegetables. Stir to coat everything evenly in the spices, cooking for 1-2 minutes until fragrant.
Pour in the diced tomatoes (with their juices) and vegetable broth. Add the rinsed black beans and stir well to combine all the ingredients.
Bring the mixture to a boil, then reduce the heat and let it simmer uncovered for about 25-30 minutes. Stir occasionally until the sweet potatoes are tender and the chili has thickened.
Season with salt and pepper to taste. If desired, add extra cayenne pepper for more heat.
Serve hot, garnished with fresh cilantro and a wedge of lime on the side for squeezing over the chili.
Notes
Adjust the cayenne pepper to taste for desired spiciness.
Keyword black bean, chili, spicy, sweet potato, vegetarian