Grind the oats (not mandatory), put them in a small cooking pot with the chia seeds and coconut flakes and then pour boiling water over them, stir well.
Then add the milk, stir and simmer on medium heat for a while (about 10 minutes), stirring a few times to make sure nothing sticks.
Turn the heat down to low and let the porridge reduce to the desired consistency.
In the meantime, mash the banana with a fork. Peel the mango, also mash half with a fork, and dice the other half into small cubes.
When the porridge is ready, stir the fruit into the porridge. Pour into a bowl, garnish with a few pieces of mango and coconut flakes.