1. Soak in water 1 day, and then cook in clear water for 40 minutes (this will soften the fish skin).

2. Then pick up the shark skin and wash it. Cleaning is the most difficult task. Wash the "sand" off the fish skin with a wire brush (be sure to brush it clean, otherwise it will be uncomfortable to eat).

3. Remove the bones and fish (all we want is gelatinous fish skin) attached to the fish skin with a knife and cut into strips.

4. Add broth and stew in a saucepan, and add a small amount of balsamic vinegar until it is stewed.