1. Add sugar to the milk and heat it to about 80 degrees to foam. The amount of sugar is adjusted according to your own taste, and milk is more than 3.5% whole milk.

2. Pour into a bowl and cool to room temperature.

3. Stir the egg whites with lemon juice.

After the milk is cooled, the surface will crust. Scrape a small mouth with a knife, pour the milk into the egg white and mix well with the egg.

Don't pour out all the milk in the bowl, leave some at the bottom of the bowl to ensure that the milk skin can float on it in the future.

6. Sieve the mixture of milk and protein twice to remove bubbles and unseparated protein.

7. Pour the screened milk rock wall back into the bowl and let the milk skin float on it.

8. Cover with plastic wrap and put in a boiling water pot. Steam on medium fire 18 minutes, and stuffy after turning off the fire 10 minutes. Let it cool, add red beans or mangoes and it tastes great.

9. Finished product

10. Eat a spoonful.