Fill a pint glass with ice. Add the remaining ingredients and stir well. Strain into a chilled martini glass. Mint Simple Syrup In a saucepan, bring 1 cup water and 1 cup sugar to a low boil, stirring until the sugar dissolves. Pour the hot syrup over a cup of clean, dry mint leaves in a heatproof container. Let steep overnight, refrigerated, then strain out the mint leaves. Refrigerate the leftover syrup for up to 2 weeks.