In a deep big Kadhai or a big saucepan, add ¼ cup of water and simmer it till you can see steam, then add milk and bring it to the boil. Adding water is the key to avoid the milk solids sticking into the bottom of the pan.
Reduce the flame on low and cook the milk with stirring occasionally, using big spoon or spatula about 40-45mins.
Scrap the edges of milk while cooking and stirring with spatula in between to remove thickened milk from sides of pan and mix it. Cook it more if you want more thicker consistency.
Then add sugar and cook it again another 40-45 mins till all milk mixture reduce into the half and become thick.
Now add cardamom powder, nutmeg powder. sliced almonds, cashew, and cook it for 7-8mins on low flame.
Basundi is ready, let it cool down then garnish it with saffron strands, sliced almond and pistachios and enjoy. You can also store in refrigerator and serve chilled.