Having played around with the recipe for Whiskey Rebellion for a few years (mostly just exchanging whiskey for other base spirits) I figured switching the Pimm's for Mr Black would be good, but wasn't too impressed with the result and moved on. However, when I first heard of the competiton I figured I'd put a bit more effort into making something of my idea, ultimately replacing every ingredient, ending up with something less quaffable than the original but, I'd like to think, more interesting.
Dissolve 2 g tartaric acid in 100 g of water
Add all ingredients and ice to shaker and shake
Strain over fresh ice
Express and garnish w. lime peel