Place sliced chilies in a heat-proof bowl. Combine vinegar, salt, and sugar in a pan and cook over medium heat until sugar and salt dissolve, then pour over the chilies. Cool to room temperature, then refrigerate. Fill a small bowl with ice, and cover the ice with water. Set aside. Place basil and cilantro leaves into the boiling water, and cook for 10 seconds. Remove the leaves with a slotted spoon and place into the ice bath. Once the leaves are cool, remove with a slotted spoon.