Peel the mango, cut away the flesh and thinly slice it.
Put the mango into a large bowl and add the black and green grapes, peaches and strawberries. Finely grind the coconut in a spice mill or with a pestle and mortar. Add the sugar, degi mirch, mustard and a pinch of salt and mix well.
Add the coconut mixture to the fruit, stir well, cover and place in the refrigerator to chill for at least 1 hour, or overnight, to allow the flavours to blend and mature.