Marinated eggs preserved in pickle sauce are a unique Songjiang local snack with residents making full use of the extra pickle sauce generated through pickle making. To cook vegetable-flavored marinated eggs, some potherb mustard is needed as an ingredient to make pickle. The pickle sauce is saved to marinate the eggs. To treat the eggs, first wash some duck eggs clean with a brush. Then place the eggs in cold water and bring to the boil, adding some salt as the water heats up. Starting with cold water prevents the eggs from cracking while they are heated, and salt can make it easier to detach the shell from the eggs later. After the eggs are boiled thoroughly, crack their shells and put them in an earthenware pot filled with pickle sauce. If the sauce is too salty, no additional salt is needed. Boil the eggs for about another four hours. No additional water is needed during the process. Avoid boiling the eggs more than once, because this would make the egg white too tough and the eggs too salty. The marinated eggs, when finished, have a unique fragrance.