Preparation: Slice off root end and half stem of spinach; wash completely and drain leaves. Wash chili pepper. Incidentally, double amount of dried chili if using plain fermented bean curd. Mash fermented bean curd with thin soy; mix with stock and sugar.
Stir-frying: Heat wok to very hot; add oil. When oil just begins to smoke, add 1/2 spinach, and toss until it begins to wilt. Push wilted spinach up side of wok; add remaining spinach, and toss until it wilts. Push all spinach out of bottom of wok; add chili and ginger; stir for about 10 seconds. Add liquid ingredients; stir; when liquids boils, thicken to medium consistency with dribbles of cornstarch paste. Recombine with spinach. Stir to coat spinach. Serve. Spinach should remain bright green until you pour in liquid.