Add milk/half and half to a pan and bring to a boil. If using whole milk, simmer and let it thicken till it becomes 3/4-1/2 in volume. If using half and half (which is already thicked), simmer for about 5-10 min. Keep stirring occasionally so that it doesn’t burn at the bottom of the pan. Remember that as the kheer cools it thickens a little more.
Add grated sweet potato and boil for another 5 min.
Stir in sugar, cardamom and saffron.
Cool before serving. Some people like it hot/warm. Before serving top with chopped nuts.