Elton John improvises song about oven manual

"We strongly recommend you read this leaflet fully from cover to cover....."

I can't find a definitive date as to when he did this. A few years ago is when it seems to have started spread on the web, but when it comes to articles about him doing this, all I come up with is dozens of posts about how he once tried to commit suicide by sticking his head in a gas oven. Erm, not exactly what I was trying to find, heh.