From About.com: Chinese Food
A famous Szechuan recipe - the name Ma Po Tofu is roughly translated as "pockmarked grandmother beancurd," named for the old woman who supposedly invented the dish.
Mix marinade ingredients. Marinate pork for about 20 minutes.
Cut the tofu (bean curd) into 1/2 inch (1 cm) square cubes, and blanch (drop into boiling water) for 2 - 3 minutes. Remove from boiling water and drain.
Chop leek or green onions into short lengths.
Heat wok and add oil. When oil is ready, add the marinated pork. Stir-fry pork until the color darkens. Add salt and stir. Add the salted black beans. Mash the beans with a cooking ladle until they blend in well with the meat. Add the chili paste, then the stock, bean curd, and leek or green onions.
Turn down the heat. Cook for 3 - 4 minutes.
While cooking, mix cornstarch, water, and soy sauce together. Add to wok and stir gently. Serve with freshly ground Szechuan pepper.