Preheat the grill and oven to 150 C (Gas Mark 2). Grill chops on a rack for 10 minutes on either side. Transfer to a casserole dish. Cook onions, mushrooms lightly in a little of the chicken stock in a pan then add to casserole with the remaining stock. Then add the apple and carrots with a little salt, pepper and herbs to taste. Cover with yoghurt and cover with potatoes then cover with foil and bake for 2 hours. Remove the foil and turn the oven up to 230 C (Gas Mark 8) and bake for a further 20 minutes. Divide into 4 portions and serve with broccoli or cabbage (optional).
If you want this dish to taste a little sweeter, try using 2 regular apples rather than a cooking apple.