Canned mangoes in its puree or pulp form may be used instead of fresh mango. The recipe requires milk although the type of milk varies - white milk, evaporated milk, or any other type of milk may be used instead of coconut milk. Whipping cream or other higher fat content milks may be used to create a richer tasting pudding. Gelatin is not required - agar, derived from seaweed, may be used instead.
Make sure your mangoes are ripe - the fruit should be bright orange or yellow and fairly soft. Scoop out the fruit, including around the stone. Place the fruit in a food processor or blender and blitz to create a smooth mango puree. Leave the mango in the processor/blender.
In a saucepan, heat up the water until it reaches a rolling bowl. Remove from heat. While stirring the water with a whisk or fork, sprinkle the gelatin over the surface of the water and stir briskly in order not to have any lumps.
Add the sugar to the hot water/gelatin mixture and stir to dissolve.
Add this mixture to the mango in the food processor/blender. Also add the coconut milk. Blitz briefly until ingredients are combined.
Outside of dim sum and other restaurants, mango pudding can also be purchased at most Asian grocery stores or supermarkets. They can be purchased as a powder, which requires the addition of boiling milk or water to the powder, or in ready-to-eat portions.