My all time favorite Chinese restaurant item - I could eat it all day, every day. This is beef and wide rice noodles (that's the chow fun part). Fresh noodles are available at most Asian markets, and definitely worth looking for. But if you can't find them fresh, the dry version like these will get you through just fine.
Beef
Sauce
For stir frying:
As with any stir frying, because it all happens quickly, have everything prepped and ready before you start cooking.