Turn Instantpot on and press SAUTE button. After it displays HOT, add oil, chopped onions, curry paste and minced ginger and garlic. Stir well till onions get translucent and you sense the aroma. ( about 3 minutes)
Add all the veggies and tofu to the pot. Sauté them for a minute. Add water and stir everything together making sure to DEGLAZE by scraping the base with spatula.
Cancel SAUTE. Close the lid with valve at SEALING. Press MANUAL or PRESSURE COOK and select 4 minute.
After Instant Pot done cooking, wait on keep warm timer for 5 minutes and then do QPR - quick pressure release by turning the valve to venting.
After the silver pin drops, carefully open the lid. Add coconut milk, sugar, salt and pepper. Give the mixture a good stir. Mix well. Your steaming hot curry is ready.
If necessary, add more water to thin the curry. Alternatively, if you feel it's too thick, simmer it back on SAUTE for couple minutes.
Add in the Thai basil leaves, cilantro leaves and chopped green onions and mix. Add lime / lemon juice just before serving. Serve this vegan Thai Massaman Curry with jasmine rice or steamed white rice, brown rice, quinoa or noodles. Enjoy!