Slice pork across the grain thinly, then cut into very thin shreds. Shed cabbage finely, too. Chop scallion. Heat 1 tablespoon lard or oil. Cook cabbage shreds for a minute. If there is a tendency to burn, add a tablespoon of water. Remove. Heat remaining lard or oil. Add scallion, then pork. Stir until pork loses all trace of pink, about a minute or two. Season with salt, sherry and soy sauce. Return cabbage and stir until thoroughly mixed and heated.