Letting rip a properly brewed grunt into the bowl (pan) of a toilet, then setting it alight, causing the grunt to ignite.

This is a dangerous sport, since one has to be virtually seated on the toilet when being lit, to stop a) the gasses from escaping due to diffusion, and b) the movement of getting off the bog blowing the gasses away.

This mostly results in gooch hair removal.
Shit! that pan flash nearly took my fucking gooch hair off!
by Steddaz October 19, 2006
Building a system of pulleys and winches with a rope and noose attached. Then, waiting for your girlfriend/boyfriend to walk through the door, ambush, and smack them over the head with a frying pan. Then, putting the pulley and winch arrangement into effect, hanging your partner up as they start to awaken from the blow to the head. While they are hanging by their neck, you get an erection and when they are just about to die as a result of asphyxiation, quickly drop them and bum them.
"Yeah, my bird came home from work last night and I flash panned her in the living room"

"Fuck off mate, I'll flash pan ya!"

"Oh your gonna get pan flashed"

"Tonight, we get Delboy off his tits and flash pan him"
by Matthew Booth April 11, 2007