Mix the pureed mango with coconut milk and a pinch of salt in a heatproof jug. In a saucepan, add water, agar-agar powder and sugar. Bring to boil until agar-agar powder has dissolved. Remove from heat and pour in the mango mixture. Stir well. and pour into a square mould or any mould... leave it to set. Once it is 3/4 set, make some grooves (lightly) on the surface of the semi set mango jelly.
Stir and bring to boil all the ingredients above, until agar-agar powder dissolves. Pour on to the mango jelly. Leave aside to cool and chill in the fridge till firm. Cut (if it is in a square mould) and serve....