Place on the middle rack in the oven and roast until the meat is 165F, about 40 to 45 minutes or so depending on your oven and the size of the chicken pieces. Check the breasts earlier and remove to a platter if finished. Cover these with foil. See Notes
Heat the remaining 2 tbsp butter in a large skillet over medium high heat. Scatter the apple slices in the pan, as much in one layer as possible. Let them sit for one minute to take on colour. Start turning and brown on all sides. Once golden brown and seared in places (adjust heat if necessary) transfer to a serving bowl. Drizzle with any remaining butter in the pan, as well as a good sprinkling of salt and pepper.
Serve the beans and cider broth in a separate bowl. Garnish with rosemary if desired. The beans and broth can also be served around the chicken if you desire.
If you don't want to cut up the chicken or can't have a butcher do it, feel free to replace with bone-in skin-on chicken pieces, between 6-8 pieces, depending on the size.
Depending on the size of the chicken this will feed 4 to 6 people. Extra large breasts can be cut in half. Dark meat has a better texture if cooked up to between 170-175F, so feel free to remove the white meat beforehand, and let the dark meat roast longer.
Serve crusty bread on the side for those who want to smoosh their garlic on bread which can also soak up the cider braised beans.