1. Scoop the flesh out of the mangoes and puree. Boil the milk and reduce it.
2. Add khoya and mix well. Add the condensed milk, sugar and mix well. Simmer the mixture for fifteen minutes or till it thickens.
3. Cool and add the mango puree and mix well. Pour into mango shells, cover with the sliced off top and freeze till set.
4. Slice and serve chilled.