I ran across this pattern at the Great Waters Fly Fishing Expo in St Paul last week. Got home and found a tutorial online. The single Gonga tutorial was posted by InTheRiffle. Charlie Craven is the inventor of the pattern. He also ties a articulated or double Gonga.
Here is a link that shows Charlie Craven tying up a Double Gonga. The video clip was posted by EbersoleMEDIA. Talk about an awesome setting.