In a large soup pot over medium-high heat, add the olive oil. Once hot, add the chopped onion and sauté for about 5 minutes until translucent and fragrant.
Add the minced garlic and ground turkey to the pot with the sautéed onions. Cook for another 5 minutes, breaking up the turkey with your spoon as it browns. During this step, I like to prep the remaining ingredients so they’re ready to go in the pot.
Add the chopped green bell pepper, diced tomatoes (with their juice), pumpkin puree, drained cannellini and red kidney beans, chili powder, smoked paprika, ground cumin, dried oregano, cayenne pepper (if using), and chicken broth to the pot. Season with salt and pepper to taste. Stir everything together to combine. Increase the heat to high until the mixture just comes to a boil, then reduce the heat and let it simmer for 10-15 minutes, stirring periodically. I like to let it simmer uncovered for a bit so the flavors meld and the chili thickens slightly.
Ladle the hot chili into bowls. Serve as-is, or top with your choice of shredded Mexican cheese, chopped cilantro, sour cream or Greek yogurt, and sliced avocado for extra flavor and creaminess. I always recommend at least a sprinkle of fresh cilantro – it adds a nice pop of brightness.