Grease a round baking tray with butter.
Make a mango puree by blending the flesh of the mangoes. Refer to the note below for removing mango pulp with ease.
Pour one-third of a cup of milk in a vessel, add the cardamom powder and bring to a boil.
With the remaining 100 ml milk, add corn flour and whisk till smooth. Ensure there are no lumps, this can seem easier than what meets the eye so take your time to whisk it well. Use a hand whisk.
Then pour the corn flour mixture into the boiling milk – gradually. Stir continuously till the mixture turns sufficiently thick yet not so thick but one of a pouring consistency.
Add the blended mango puree to the milk-cornflour mixture stirring gently.
Soon after, add the sugar and continue to stir till the sugar has melted and is well ensconced in the mixture.
Turn off the heat and pour the pulpy mixture into the pre-greased tray (you may strain the pulp before it goes into the tray). Let sit till cool. Then refrigerate till well set.
Remove from fridge after an hour or two, do the knife test before overturning the pulp on a dish. Run a thin knife along the sides till it’s got space enough to drop onto the dish with a soft lop. Cut out soft triangles and serve your guests or yourself.