1/3 cup fresh lime juice, plus 2 lime slices, quartered
1/4 cup simple syrup (see Note)
6 mint sprigs, coarsely chopped, plus 2 long sprigs
In a cocktail shaker, mix the vodka, lime juice, simple syrup and chopped mint and strain into 2 glasses filled with small ice cubes. Garnish with the lime slices and mint sprigs and serve.
To make the simple syrup, simmer 1 cup of sugar and 1 cup of water in a saucepan over moderate heat, stirring, until clear, about 1 minute. Let cool. A batch (about 1 1/2 cups) will keep in your refrigerator for up to 1 month.