Nando's is a South African chain. Quality isn't what it was fifteen years ago though. However, they do some fabulous TV commercials if you search youtube!

Hi Nando's isn't common in the U.S. where most foodpicklers generally, but not always, are. There are just 2, I think. But they do seem to like a line of bottled sauces. Nando's doesn't give out their recipe. But if you search the internet, you will find 'copycat' recipes like this:
http://bbqmasala.com/2009/07/30/flame-broiled-nandos-chicken-nandos-chicken/