Set the Instant Pot on saute mode, and when the display shows "HOT," add the coconut oil.
After 30 seconds, add the mustard seeds, cumin seeds, slit green chilies and curry leaves. Let the mustard seeds sputter.
Then add the ½ cup of water. Next, add the ashgourd and salt. Mix thoroughly.
Now press the cancel button and close the Instant Pot. Make sure the vent is in the sealing position. Pressure cook for 2 minutes at high-pressure mode. When the cooking is complete, wait for 5 minutes and release the pressure quickly.
After the pressure is all released, carefully open the lid. Set the Instant Pot back to saute mode and mix the vegetable.
In a bowl, mix the coconut milk and rice flour. Make sure there aren't any lumps.
Add this coconut milk, rice flour mixture to the white pumpkin.
Mix and let it simmer for 5 to 7 minutes.
The stew will thicken slowly. After five to seven minutes, turn off the Instant Pot and serve this warm with rice.
Other Vegetable Substitutes: Instead of white pumpkin, you can use yellow cucumber, bottle gourd, butternut squash, or red pumpkin. For a soft yet firm vegetable, you can follow the same Instant Pot cooking time, or if you prefer a very soft veggie texture, you can increase timing by one or two. But I would recommend starting with two minutes and depending upon the doneness, increase the cooking time.
Cooking Time: I prefer soft, yet firm vegetables for my kootu. So my cooking time is less. But if you prefer the soft texture, either release the pressure naturally or cook for three minutes and release the pressure after 5 minutes.
Instead of rice flour, you can use corn starch to thicken the stew. Traditional recipes call for rice flour, but you can opt corn starch as well.
If you prefer thin stew, either add ½ more cup additional water or reduce the flour measure by ½ tsp.
Lite coconut milk or full-fat coconut milk? When I first tried this recipe, I went with lite coconut milk. It was not creamy like this one, and you can see my first version on my Instagram feed as well. As I wanted it creamier, I went with full fat this time. But you can choose either one. I went with store-bought coconut milk.
As always, adjust the spices according to your preference.
Pressure Cooker Version: If you are making this in the pressure cooker, then cook the white pumpkin for only two whistles. Right after tempering, add ½ cup of water and the vegetables. Pressure cook for two whistles and release the pressure naturally. Then add the coconut milk mixture and simmer.
Curry leaves enhance the flavor of the recipe. But if you can source it, ignore or add some cilantro. But the taste will be different for sure. For this coconut milk stew, I either add curry leaves or cilantro.