In a small bowl, pour 4 cups of boiling water over mint leaves. Let steep for 10 minutes. Strain and cool.
Meanwhile, in a 1-2 quart saucepan, over medium-high heat, bring to a boil cranberrries, sugar and 1 cup of water. Remove from heat. Cool then strain.
To make one cocktail, combine 1/3 cup fresh mint tea, 2 tablespoons cranberry syrup, 1 tablespoon limoncello, 2 tablespoons vodka and 1/2 teaspoon lemon juice in a cocktail shaker full of ice. Shake vigorously and strain into a martini glass.