KHOYA: Boil the milk in a large thick bottomed pan on a low to medium flame.
Now lower the flame and simmer the milk. Stir at intervals whilst the milk is simmering.
The milk will froth many times, while its being simmered. So when you see this happening, stir the milk with a spatula and scrape the milk solids from the sides and add to the milk.
When the milk is reduced to half, add sugar and keep stirring.
Towards the end when the milk has reduced much, you will see bubbles bursting in the reduced milk. At this point continuously stir. If you don't then the reduced milk will get browned or burnt. The bubbles are due to moisture in the milk.
When you see no bubbles in the reduced milk, its time to switch off the flame.
Transfer the khoya to a bowl, cover and let the khoya cool at room temperature.
RABRI: To the same pan used for the khoya, add another 1 Liter milk and sugar.
Following the same process mentioned above, reduce the milk to half. Rabri is ready.
ROLLS: Cut the crust of the bread slices and place khoya on one side. Roll into a thin roll.
Arrange the rolls in a serving dish and pour “hot rabri” on top.
Sprinkle chopped pistachios and some saffron on top.
Cover and allow to cool at room temperature so that the bread slices absorb the rabri. Now place in the refrigerator.