The recipe as remembered:

One generous shot of over-proof rum
Two heaped teaspoons of Jello crystals (any flavour will do, but high on the preferred list is cherry)

Top up with boiling water.

For complete enjoyment the drink should be taken in a ski-camp at a temperature below -20C by the side of a blazing fire.

(For the Brits - Jelly in Canada comes as a powder, rather like sugar,
instead of the flavoured rubber sheets sold in the UK, but I expect a
couple of squares would substitute OK)

Thanks to Ian Drummond for this one.