Lemon Tarragon Fizz

In a saucepan over low heat, make the tarragon syrup by dissolving 2 cups sugar in 2 cups water. 

Add 1 cup chopped fresh tarragon leaves. Remove from heat and set aside to infuse for 15 minutes.

Let cool completely, then strain into a small carafe. 

Pour 5 cups fresh lemon juice and 1 (1.5-liter) bottle lemon-lime soda or club soda into a pitcher filled with ice. Sweeten with 1/2 cup tarragon syrup. 

Place extra syrup in a carafe to let guests sweeten their drinks to taste. 

Garnish with lemon slices and fresh tarragon, if desired.