Did you try it in the Chao Bar in the Pigalle area? If so, me and some friends
had the same thing last October. According to the menu it was gin, lychee
liqueur and fresh ginger - I made a note of the recipe before leaving.
I would make it as follows...
1 1/2 measures London dry gin
1/2 measure lychee liqueuer (Soho is the brand used in the drink)
1 teaspoon of fresh ginger, cut into very small cubes
Either muddle the ginger with the lychee liqueur and then add the gin with ice
or shake and pour all the ingredients into an old fashioned/rocks glass.
Either way, it's garnished with a fresh lychee.
I hope this helps.