Add all the vegetables with the turmeric, salt and water to the Instant Pot. Set it to Manual and close and cook sealed under pressure for 4 mins.
Quick release the pressure as soon as 4 mins is up. Be sure to watch for the steam as you do the pressure release.
Grind together the coconut, cumin, green chillies and yogurt to a fine paste.
Add this paste to the cooked vegetables. Cook in saute mode for 2 mins, till it all comes together.
Garnish/season with the coconut oil and curry leaves.
You can use other vegetables like the small eggplant, other squashes or melons etc. This is usually the combination I use.
Yogurt is used as the souring agent here. In certain parts of Kerala, tamarind is used as the souring agent instead. If using tamarind, use a lime sized ball, soak in water and take out the pulp. Add this to the vegetables when they are cooking. Skip the yogurt. Grind the coconut with a little water instead.
If using frozen coconut, microwave the frozen grated coconut for 30 secs or so. This way the coconut seems to grind better without having fat solids stuck in the mixer/food processor.