Brown the rabbit joints in the fat in a flameproof casserole and season with salt and pepper. Lower the heat and add the onion, rosemary and bay leaf and cook for 5 minutes. Add the cider and a pinch of sugar. Increase the heat, bring the liquid to the boil and simmer for 4 minutes or so. Lower the heat, cover the casserole and simmer for 45 minutes or until the rabbit is tender.