Blanch and peel the nuts (where necessary). Set a few almonds and pistachios aside. Grind the remaining nuts, and slice the raisins. Mix the semolina and milk with a tblsp of ghee. Set aside for 2 hours. Add a cup of water to the sugar and prepare a thick syrup. Remove fan fire, and mix in the khoya, nuts and raisins. Stir till smooth. Pour into the semolina, adding the remaining ghee, and keep stirring till the mixture is smooth and free of lumps. Mix in the saffron, cardamom and nutmeg and remove into a flat, well-greased baking dish. Garnish all over with the almonds and pistachios (kept aside earlier). Bake in a moderate oven till golden on top. Insert a toothpick in the center of the roti. If it comes out clean, remove from the oven; if not, bake a little longer. Then cool, cover with foil and cut into small slices before serving.