In a 4-quart or larger slow cooker, place the chicken thighs, then sprinkle with cumin, chipotle chili pepper, oregano, 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.
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.
Preheat your oven to 350 degrees F. Cut each tortilla into 6 wedges, then arrange in a single layer on two ungreased baking sheets. Bake for 6 minutes, then with tongs (or quickly and carefully with your fingers), flip and sprinkle with salt. Rotate the pans between the top and bottom racks, then bake the chips an additional 6 to 9 minutes, until they are just beginning to turn golden. Remove from the oven and let cool. Turn the oven to broil.
Arrange the cooled tortilla chips on an oven-proof serving platter or pile all of them onto a single baking sheet. Spoon the chicken and bean mixture over the chips. Sprinkle with cheese, then place under the broiler for a few minutes, until the cheese is melted and bubbly. Remove from oven, then sprinkle with any additional desired nacho toppings. Enjoy immediately.