Boil sugar and water 5 minutes and let cool. 

Muddle leaves with a pestle. Add to syrup. Refrigerate overnight. Strain muddled leaves. 

Fill glass with shaved ice. Add bourbon (100 proof). Add 1 teaspoon of the syrup or more to taste. Stir wit a sprig of fresh mint. 2 parts bourbon to 1 part syrup is the recommendation.