Heat a large skillet over high heat and lightly spray with oil. Add ground turkey and cook, breaking it up until no longer pink, about 5 minutes. Transfer the cooked turkey to the slow cooker.

Add olive oil to the same skillet. Add chopped onion and sauté for 3-4 minutes until softened. Add minced garlic and cook for another minute until fragrant. Stir in cumin and cook for another minute. Transfer the onion and garlic mixture to the slow cooker.

Add the rinsed and drained white beans, pumpkin puree, chopped green chiles, chicken broth, chili powder, oregano, and bay leaves to the slow cooker. Stir everything together.

Cover and cook on high for 4 hours or on low for 8 hours. Before serving, remove the bay leaves and season with kosher salt and pepper to taste.

Serve hot, garnished with fresh cilantro, red onion, or chives, and a dollop of Greek yogurt or sour cream, if desired.