To make the bottom layer, squeeze off excess liquid from the grated tapioca and combine with sugar, salt and thick coconut milk in a non-stick pan. Cook over low heat until mixture turns into a thick batter. Pour the batter into a lightly-greased 23cm square tray. Steam for 20 minutes.
For the top layer, combine the different types of flour, salt and coconut milk in a non-stick pan. Cook until mixture turns into a soft paste-like batter. Pour batter over the tapioca layer and steam for 15-20 minutes.
Remove the talam from the steamer and let it cool completely before cutting into square serving pieces.