Grind together 1tsp sugar along with 4 small cardamoms.
Heat 1 liter milk in a deep skillet along with 2 cups of sugar, small cardamoms and 1 cup mashed boiled rice. Cook the milk over a low flame
Peel and mash the boiled sweet potatoes. When the milk begins to boil stir in the mashed sweet potatoes. Stir continuously
In 1 cup of milk, stir in 3tbsps of vanilla custard powder and mix well till a smooth paste is formed. Pour the paste into the milk mixture stirring continuously.
Pour the kheer into a serving dish, garnish with sliced almonds , pistachios and crumbled khoya.