I have attempted to make thai beef meat balls for about 10 times now and failed almost everytime. Thai beef meat balls need to be stretchy and have a chewy texture when finished.   I have tried mince with no fat, mince with 10% fat, high quality mince with no fat, still cannot get the right finished texture like the one in this video: Thai Beef Meatball Recipe  So I was wondering, what does cornflour and baking power do to the mince?  Why is it so necessary to have the mixed mince very cold before shaping it into a hot water?   I have followed exactly what the above video says and still cannot get it right. 
I read the key is to keep the meat cold and to put in the freezer to keep it that way then take it out before it freezes solid and you do this several times during the process right up to cooking.   