Yumm. Must definitely try.
I used a combination of several recipes, here are the best ones I've found:
Rasa Malaysia's (the best Asian food blog on this planet) and a simpler version with less ingredients at Recipe Zaar. I didn't "fry" the beef in too much oil, so the beef didn't have the traditionally yummy crust outside. So, if you want it to be more authentic, make sure you don't skimp on the oil :)