Dice the onion and bell pepper into small, even pieces. Mince the garlic finely. Rinse and drain the canned black beans to remove excess sodium.
Heat the olive oil in your large pot over medium heat. Add the diced onion and bell pepper, cooking until softened and fragrant, about 5 minutes. Stir in the minced garlic and cook for another 1-2 minutes, taking care not to let it burn.
Sprinkle in the chili powder, cumin, smoked paprika, salt, and pepper. Stir to coat the vegetables evenly and toast the spices slightly to unlock their full flavor.
Pour in the pumpkin puree, diced tomatoes, black beans, and vegetable broth. Stir everything together thoroughly.
Bring the mixture to a gentle boil, then reduce heat to low and simmer uncovered for 25-30 minutes, stirring occasionally to prevent sticking.
Taste and adjust seasoning as needed, adding more salt or chili powder for extra flavor or heat.
Ladle the chili into bowls and garnish with freshly chopped cilantro. Serve alone or with crusty bread, rice, or tortillas.