Bring 2 cups of water to a boil in a saucepan.
Add Thai tea leaves or Thai tea mix and simmer for 3–5 minutes.
Turn off the heat and allow the tea to steep for another 5 minutes.
Strain the tea into a jug.
Add sugar and stir until completely dissolved.
Allow the tea to cool, then refrigerate for 30 minutes.
Fill serving glasses with ice cubes.
Pour the chilled tea over the ice.
Add condensed milk and evaporated milk.
Stir gently and serve cold.