Combine whiskey, triple sec, strawberry puree and agave sour mix in shaker with ice. Cover; shake vigorously. Strain into 14 oz. glass filled with ice. Garnish with strawberry, if desired.
Fresh Agave Sour Mix: Combine 1 cup fresh lemon juice, 1 cup fresh lime juice, 1 cup water and 1-1/2 cups agave nectar in 1/2 gallon container. Stir until well blended. Cover; refrigerate until ready to use. Makes 4-1/2 cups.