Heat the avocado oil in a large pot or Dutch oven over medium heat. Add the onion and red and green bell peppers. Cook for 5–7 minutes, until softened. Add the garlic and cook for about 30 seconds, until fragrant.
Add the ground turkey, breaking it apart with a wooden spoon. Cook for 6–8 minutes, until browned and cooked through.
Stir in the chili powder, cumin, oregano, smoked paprika, and Ceylon cinnamon, if using. Cook for 1–2 minutes, stirring, to allow the spices to bloom.
Add the diced tomatoes, red kidney beans, light kidney beans, cannellini beans, chicken bone broth, maple syrup, salt, and fresh cilantro. Stir well to combine.
Stir in the ground flaxseed. Reduce the heat to low and simmer uncovered for 25–30 minutes, stirring occasionally, until the chili has thickened and the flavors have come together.
Taste and adjust the salt or seasonings as needed.
Ladle the chili into bowls. For each serving, top with 2 tablespoons Greek yogurt, about ⅓ of an avocado, 1 tablespoon pepitas, additional fresh cilantro, and a squeeze of fresh lime.