Once the chicken is tender, use two forks to shred it in the slow cooker. Stir in the pinto beans. Cover and let cook on high for 30 minutes to warm the beans while you prepare the tortilla chips.
In a 4-quart or larger slow cooker, place the chicken thighs, then sprinkle with cumin, chipotle chili pepper, garlic, and salt. Add the poblano (if using), then pour the salsa verde over the top. Coved and cook on high for 2-3 hours or low for 5-6 hours, until the chicken is tender and cooked through.