How to make black fish fillets tender?

For sizing, first add some salt and MSG to the fish fillets and shredded pork. Add a little pine meat powder, grasp it with your hands, then add water, the proportion of water is. Add 4 ounces of water to 1 kilogram of meat. After the meat is cooked, add starch and it is OK. Note, if you are not going to use it that day, sprinkle a layer of oil on top of the meat! ! ! I will use it in a few days and the effect will be the same, haha! ! ! ! Supplementary answer: I am talking about the method in the hotel. By the way, I need to add a few eggs to it! ! The meat will be better this way