Usually stew for an hour or two. If it is a pressure cooker, it takes 15 minutes after exhausting; For casserole, simmer for about an hour; An ordinary pot takes one and a half to two hours. The practice of trotter soup: 1. Wash the pig's feet with clear water, add cold water to the pot, and turn off the fire after the fire boils. Take out the cooked trotters and wash them again. Cooked pig's trotters have no fishy smell and blood foam, and are whiter after stewing. Sliced ginger, diced carrots and lettuce. 3. Wash the saucepan, add the cooked trotters, add the cold water twice as much as the trotters, add the ginger, cook for 10 minutes on high fire, and then turn the heat to slow three for 10 minutes. 4. Add carrots and lettuce pieces and continue to stew for ten minutes. 5. Put some salt and sprinkle with chopped green onion.