Peel and wash and roughly chop onions.
In a food processor add ginger, garlic, green chillies and chopped onions, and grind to a smooth paste.
Roughly chop tomatoes and grind in food processor.
Switch on the Instant Pot on SAUTE MODE. Set the timer for 10 minutes.
Add oil in inner pot. When the display shows hot, add oil. If using mustard oil heat till the smoking point, else add cumin seeds.
Ince the seeds crackle, add onion paste. Fry till light golden brown. While frying onions, keep on scraping the bottom of inner pot as onion paste can stick there and burn.
Once onions are done, add tomato puree. Mix everything well.
Canel the SAUTE MODE.Cover the lid and set the PRESSURE COOK Mode on for 2 or 3 minutes(depends how fine is tomato puree)..
Once the timer goes off, do the QPR(quick pressure release), open the lid.
If there is some extra water, in masala, switch on the saute mode again for another 5 mins, and cook masala till water dries up.
Cool it and pack it in portions in an ice tray or silicone baking cups as shown in pic, and freeze it or refrigerate it in a airtight container.
Use as and when required.