Strain through double thickness of cheesecloth, squeezing out just as much of the milk as possible, about 3 cups. Mix cornstarch with sugar and add sufficient coconut milk to make a smooth paste. Boil until it thickens. Pour into mold and allow to cool. Cut into squares and serve on squares of ti- leaves.
Substitute spinach leaves if no ti-leaves are available or serve on bamboo plates or glass platters.