If using the optional ingredients (given in the ingredients list as optional) for more traditional flavor, add the ghee to the instant pot and press saute.
As the ghee begins to melt, add raisins and cashews, lightly fry for few seconds.
Press cancel to stop saute function and then add roasted vermicelli (if you are not using roasted vermicelli, you may saute the vermicelli also in the ghee for few seconds).
If you are not using the optional ingredients, you can skip the first two steps and directly add the roasted vermicelli to the instant pot (no need to use saute function).
Add water, milk and cardamom powder also to the instant pot and stir the contents to make sure vermicelli noodles are not stuck at the bottom of the pot.
Close the instant pot with lid in sealing position and cook in high pressure for 2 minutes. Once the cooking is done, press cancel and wait for a natural pressure release for about 10 minutes.
Once ten minutes of natural pressure release is over, carefully do a gradual manual pressure release to release any remaining pressure.
Once the pressure is all released, carefully open the lid and add the sweetened condensed milk to the pot. Stir well to combine and transfer the inner pot to a cooler place so the vermicelli won't get overcooked.
The kheer will further thicken as it cools down, you may add little more milk later if needed, to adjust the consistency of the kheer. If the kheer is too thick for your preference, add chilled milk so it will not thicken much further.
Serve the vermicelli kheer warm or chilled as you like!