Peel potatoes and boil until tender, drain and return to hot pot. Mash with cider and cream, and season with cinnamon, nutmeg, salt and pepper.
While potatoes cook, heat EVOO in cast-iron or stainless steel skillet. Add chicken to hot pan and cook 10 minutes, turning once. Transfer chicken to plate and deglaze pan with vinegar. Whisk in marmalade, stock and herbs. Add chicken back to skillet and turn in the sauce. Let thicken 1-2 minutes then serve with mashed sweet potatoes alongside.