Tender beef

How do they make wok,d beef so tender at Chinese restaurants?

there is a method of velveting that they do for their stir fry beef and chicken and pork

usually the meat is partially frozen so that it can be sliced so thin and they cut across the grain to make it tender

to velvet their beef *not all use the same method - but this is one way to do it - they make a mix of egg white and cornstarch into a slurry and let the meat marinate in it for about 20 minutes then it is either cooked very briefly (about a minute) in oil or simmered in some hot water with a bit of oil - then they add it to the stir fry to cook

to tenderize their chicken or pork (velvet) it is usually a combination of water and oil

if the meat has a sponge-type texture - then they added baking soda to the marinade - the baking soda helps to tenderize as well

adding baking soda to veggies will make them softer as well

and don’t forget - there are chemical meat tenderizers than can also be used

some cooks add a bit of vinegar to tenderize meats -
it’s all your preference

I hope this helps -