While honeymooning in Canada, my wife and I had an incredible cocktail at Cork & Fin in The Gastown district of Vancouver. My wife tried to recreate it, but instead came up with her own version. This drink has since become our favorite cocktail!! Cheers!
1 oz Hendricks Gin
1 oz St. Germain
1 oz fresh grapefruit juice (not from concentrate)
Q tonic water
Put the Hendricks, St. Germain, and grapefruit juice into a shaker with ice. Shake well, and pour into a martini glass. Top of glass with "Q" tonic water.
We have tried to make this drink with different Gins/elderflower liqueurs. You will not achieve anywhere near the same taste without using these exact ingredients.