Place whole mangoes (not skinned) in a large pan 3/4 full with water. The skin works as a casing, ensuring the pulp doesn't go everywhere
Cover and bring to a boil over medium heat.
Simmer for 20-25 minutes.
In a mortar and pestle, grind up your cardamom, until it becomes a powder.
Take your jaggery and with a knife cut, until you get ~ 1 cup.
After 20-25 minutes, the flesh should be soft and the skins should be loose and yellowy. Test with a knife, it should go into the skin easily. Turn off the heat.
Drain off the water in the sink over a colander, cool the mangoes (10 minutes), peel the skin off with your hands or with a spoon. Then put the pulpy flesh into a bowl. Optional: Squeeze the pulp off the stones and place in another bowl with a little warm water, to extract more pulp.
Add the jaggery into the pulp, mash the two together until smooth with the butter churner (or potato masher) - it makes it easier for the sugar to melt in the still warm pulp.
Stir in cardamom, saffron and salt with a ladle.
Ladel in the concentrate - around 2-3 heaping spoonfuls or more as desired
Fill the rest of the way with water and then add your ice cubes