You need two people. Measurements are hazy but what you do is fill a shot glass almost to brim with rum. Put glass on saucer. Next add Green Chartreuse so that the drink spills into saucer for a while. Before settles, light the shot glass, holding a glass above the flames until they die out. Quickly get someone to cover the glass to trap the gas, whilst you drink, first the shot with a straw, then the saucer also with the straw. Quickly get your friend to, when your ready, leave a gap protecting the fumes so you can shove your straw into the glass and inhale. Believe me its worth the hassle
Serve in a Shot Glass