Pour chicken or turkey broth in a 6-quart slow cooker.
Stir in the beans, poblano pepper, garlic, cumin, and chili powder.
Cover and cook on LOW for 6 hours, or until beans are tender.
Uncover and remove 1 cup of the cooked beans and transfer to a bowl.
Mash the beans with the back of a fork.
Return the mashed beans to the slow cooker.
Add in the shredded (cooked) turkey meat, and stir in the chopped green chiles, salt, and pepper.
Cover and cook on LOW for 10 minutes.
Stir in the corn kernels and ½ cup of sour cream; continue to stir until the cream is well combined. Taste for salt and pepper and adjust accordingly.
Ladle chili into bowls and top with jalapeno slices, cilantro leaves, cheese, remaining sour cream, and avocado slices.