Soak the soybean for 1 hour. Chop the pork leg and blanch to remove the blood foam. Heat the vegetable oil in a pan, sauté the ginger and garlic until there is aroma. Add the pork leg and sauté until the skin of the pork turns to golden. Add the rice wine, the soybean paste, the light soy sauce, the dark soy sauce, the rock candy and salt. Stir to make the paste evenly cover each piece of the pork. Add the soybean and stir. Add hot water to just immerse the materials. After boiled, add the chopped carrot. Cover and cook in slow fire until the pork leg becomes soft and the paste sticky.