Shake all ingredients together. Strain into a chilled coupe and garnish with a mint leaf.
Place a bowl filled ¾ with water into a stockpot. Add fresh mint to cover the bottom of stockpot and enough water to cover mint. The water in the stockpot should come up to the halfway mark on the bowl. Then, place another bowl on top of the bowl that's positioned in the bottom of the stock pot. Begin simmering the water in the stock pot on low. Place a steel bowl on top of the stockpot to seal in the steam and fill that top bowl with ice. Allow to simmer for about 4 hours, adding ice to bowl to keep it cold.
The hot steam hits the cold bowl, condensing the oil and steam which then drip down into the empty bowl. To separate the oil from the water, freeze the mixture and separate after water has frozen.