Start by chopping the onion, bell pepper, and mincing the garlic. If using fresh pumpkin, prepare it by peeling and cubing, then roasting or steaming it until tender before pureeing.

In a skillet, heat the olive oil over medium heat. Add the diced onion, bell pepper, and minced garlic. Sauté for about 5-7 minutes, until the vegetables are tender and fragrant.

Transfer the sautéed vegetables into the slow cooker. Add the pumpkin puree, both beans, diced tomatoes (with their juice), vegetable broth, chili powder, cumin, smoked paprika, cinnamon, salt, black pepper, and cayenne pepper (if using).

Stir all the ingredients until well combined. Make sure that the pumpkin puree is evenly distributed throughout the mixture for consistent flavor.

Cover the slow cooker with the lid and cook on high for 4 hours or on low for 6-8 hours, until all the flavors meld together and the chili thickens to your desired consistency.

About 30 minutes before serving, taste the chili and adjust the seasoning if needed. This might be a good time to add more salt, cumin, or spices based on your preference.

Once cooking is complete, ladle the chili into bowls. Serve with your choice of toppings such as sliced avocado, a dollop of sour cream, shredded cheese, chopped cilantro, or sliced green onions.

This slow-cooker pumpkin chili is hearty enough to be a meal on its own, but pairs well with crusty bread or a side salad.