How to duplicate the soft cut of steak in Thai food?

From what I have cooked and read thus far, you don't rinse off the cornstarch. It acts as a seal to keep the protein soft and not used as a tenderizer.

Oftentimes grocery store steaks are portioned in a way that means when you slice it, you're actually slicing with the grain instead of against it. This means chewy meat. Try buying a larger cut of meat and breaking it down yourself. I have never tried it for beef, but when I do chicken sir-frys I marinate the chicken in baking soda for 1 hour before cooking, Rinse off the baking soda before using the meat, It acts as a tenderizer.

Hi Sam, I have been velveting chicken and beef to replicate my favorite Chinese dishes with great success. Found so many tutorials and blogs about the technique and I'm in love. So a big thank you to you!

I never knew about 'velveting'. I've always used a good marbled cut of beef, sliced, and fried fast enough to still be m/r pink inside. I'll stick with that but will try velveting with pork for some satay skewers.

There's a stir fry method that's used in Chineese cooking, and sometimes Thai cooking called "Velveting".
Basically, it's encasing the thinly sliced meat in marinaded.
Of egg white and seasonings (in thai that would be lemon grass and galagala (or ginger), ginger). Then after a hour or so, coat with corn starch and either fry or par-boil and put in the stir fry with other items for final tossing and saucing. The coating protects the meat from the heat and keeps it moist.
Look up Velveting meats for more info and techs.

Have you had any luck with flank steak, grilled, and thinly cut against the grain? I usually use either flank or top sirloin for Thai beef salads.