Barfi Pista (Creamed Milk Sweetmeat)

Preparation : Sift the powdered milk. Gradually mix in the water, bring to the boil and cook over a moderate heat, stirring continuously, until reduced to a very thick paste. Make a thick syrup with the sugar and a little water, and add to the creamed milk. Add ground pistachios and stir thoroughly. Cook again until it is a thick paste. Turn into square shallow tins or dishes, spreading about 2 inches thick. Leave to stand for 8 hours. Press into it roughly broken cardamom seeds and slivered pistachio. Cut into diamond shapes to serve.