I've seen a lot of people talk about this, but I don't think this translation of "garest" is right . I speak german and as far as i know the correct word for "to cook" would be "garen". Though it is a form of it, "garest" does not make much sense in context, since it would be "du garest", meaning "you are cooking". So I don't really think he's talking of cooking. But I could be wrong.
I've listened to the audio several times and couldn't understand anything else, sorry.