Wash the mango with cold running water and peel.
Pour coconut milk into a saucepan, add sugar, cinnamon and bring to a boil. Don't forget to stir periodically. As soon as the milk boils, pour in the oatmeal. Bring to a boil and cook until done. Cooking time depends on the degree of processing of the oat grains. Therefore, follow the instructions on the package.
Fry the pistachios in a dry frying pan. Clean and chop them. Cut the prepared mango into two parts. Cut half into small cubes and add to the porridge. Use the other half for decoration. Place the prepared pistachios, mangoes and coconut flakes into the pan with the porridge and stir.
Serve the oatmeal hot as an independent dish. When serving portioned, place it on a plate; top with thin slices of mango and pistachios.