Thai Iced Lemongrass and Pandan Tea

Ingredients
5 stalks lemongrass (cut slantly)
5 pandan leaves (make a knot)
1/4 cup yellow rock sugar (you may put lesser or more to suit your liking)
1.5-2 L water

Method
1. Put water in a big pot and bring it to boil, add lemongrass and pandan leaves. Cook for about 30 minutes (using low fire).
2. Add yellow rock sugar and cook until it's all melted. Cover the pot and let it sit for a while before serving it with ice cubes.