Eggs, milk, low-gluten flour, fine sugar, fresh lemon

Separate egg white from egg yolk, add sugar to egg white, squeeze a few drops of fresh lemon and beat well, add sugar to egg yolk, mix with flour and milk, then add beaten egg white, stir into paste, and pour into a container for baking.

With the right amount of ingredients, you don't need to be so precise. If you are not sure whether it is cooked, you can test it with a toothpick. If you don't touch the immature batter after pulling it out, you can.