Combine chicken, green beans, sweet potato, bell pepper, onion, garlic, and ginger in a slow cooker.
Stir together chicken broth, curry powder, kosher salt, cumin, turmeric, and cayenne pepper in a small bowl. Pour into slow cooker and stir into chicken and vegetables. Cover slow cooker.
Cook on Low until chicken is cooked through and vegetables are fork tender, about 6 hours.
Whisk together coconut milk and cashew butter in a bowl until all the lumps are gone. Add to slow cooker and continue cooking for 1 more hour. Garnish with chopped cashews and cilantro.