Very lean meats, such as veal and game birds, and very small joints of any meat, need extra fat when they are roasted or they become dry and tough. Continual basting is time consuming, and opening the oven door lowers the temperatures. The answer is to make a roast 'self-basting', by barding or larding it.
Barding involves covering the joint with a layer of fat, which melts over the meat as it cooks. Pork back fat is the most suitable as it does not have a strong flavor, but some game birds are barded with streaky bacon, tied into place.
Larding involves threading strips of pork back fat through the meat with a larding needle. It is particularly suitable for large joints which need a long cooking time as the fat slowly dissolves, basting the meat internally and adding extra richness to the meat juices.
** Asian Recipes