Heat the olive oil in a large Dutch oven over medium heat. Add the diced onion and bell pepper, cooking until softened before stirring in the garlic for another minute.
Mix in the tomato paste, chili powder, cumin, smoked paprika, and oregano. Cook briefly until the spices become fragrant, then stir in the pumpkin purée, diced tomatoes, vegetable broth, black beans, kidney beans, and corn.
Bring the chili to a gentle simmer, then reduce the heat and cook uncovered, stirring occasionally, until the flavors meld together and the chili thickens.
Taste and adjust the seasoning with salt and black pepper as needed. If you'd like a thinner consistency, stir in a little extra vegetable broth before serving.
Ladle the chili into bowls and finish with your favorite toppings such as shredded cheddar, sour cream, cilantro, avocado, pumpkin seeds, or a squeeze of fresh lime.
