I bought 2 bags of 250g oysters and drained it, and it's a little over 330g. Rinse oysters gently in light salt water, support with a sieve and drain. Slice the garlic and chop the onions. Place oysters in appropriate glass containers and place sliced garlic evenly on top.

Place onions on top of garlic and sprinkle with bay salt.

Lastly, you can finish by pouring soy sauce. Turn the lid upside down and leave it in the refrigerator for about 2 days. It is the process of aging oysters and other ingredients to blend together.

I took it out of the refrigerator after two days. When you open the lid, the strong soy sauce and oyster smell come out.

The firm oysters have become mushy.

Strain the ingredients through a sieve and take out only the soup.

It's good to sterilize the bottles of sauce or sauce that will be used for a long time. Put the storage container (glass) in boiling water and sterilize it with hot water. Don't drain it and put it upside down. You have to dry it right away

Add sugar to the sifted broth and bring to a boil over medium heat. If you leave it to boil without stirring, the foam will rise. Boil for about 20 minutes, removing the foam from time to time. It should be okay if the sauce gets on the spoon and drips slightly. If you cool it down and store it in the refrigerator, it becomes thicker, so you can adjust the concentration considering that.

When the concentration is right, put it in a hot sterilized glass container and turn it upside down with the lid closed. When it cools down to a certain extent, you can set it up and store it in the refrigerator. It's a sauce with some soy sauce and sugar, so I think you can keep it for more than a month