In a small saucepan, bring 3 cups water and tea bags to a boil, remove the saucepan from the heat, and set aside for 5 minutes to allow the tea to steep. Remove the tea bags and discard them, and allow the tea to cool completely. In a pitcher, combine the brewed tea and the remaining 2 cups water, along with the remaining ingredients, except for the garnishes, and stir well to combine. Place the pitcher in the refrigerator and allow the mixture to chill for 30 minutes or more to allow the flavors to blend. Serve in ice-filled glasses and garnish each with a lemon slice and sprig of mint.