Combine the water and chia seeds in a bowl and stir well for a couple of minutes.
Set aside for 20-30 minutes to allow the gel to set. Stir 3 or 4 times.
Put the mango pulp, coconut milk and vanilla in a blender and whiz until smooth and creamy.
Add about half of the chia gel and evenly mix through the pudding.
Divide the pudding evenly into two bowls. Decorate with a handful of your favourite nuts and a sprinkle of coconut flakes.
When making the chia gel, start with 1 cup of water and add more at the end if the seeds don't look like they're fully expanded.
Keep any leftover gel in the fridge to use in smoothies or baking.
If you prefer, you can use Greek yoghurt instead of coconut milk.