Select sauté on the instant pot and adjust to normal.
Add oil to the pot.
When the oil is hot add the mustard seeds, urad dal, chana dal, serrano pepper,and curry leaves.
When the mustard seeds splutter add the asafoetida.
Then in 30 seconds add the chopped onions. Keep stirring in order to prevent the onions from burning.
When the onions turn golden in about 2 to 4 minutes add the ginger garlic paste. Stir.
Add the frozen mixed vegetables, cashews, and sauté for a minute.
Add the roasted vermicelli, water, salt and ground turmeric. Make sure nothing is stuck to the bottom of the pot and scrape the bottom of the pot well.
Secure the lid on the pot and close the pressure-release valve.
Select manual and cook at high pressure for 1 minute.
Release the pressure naturally for 4 minutes. Then quick release the pressure.
Transfer the vermicelli in a serving bowl.