First, buy 25kg of pig bones, wash them clean, then chop them up, pick out the bone marrow with chopsticks and put them in a big pot, then add 1kg of fish meal, half a catty of dried shrimps and 4-5 slices of ginger (even skin), put two pieces of dried tangerine peel into the pot together, then put about 6kg of water in it, then spend the night in a coal stove, then get up the next day and season them, adding a small amount of salt, chicken powder and monosodium glutamate.