Press sauté and add the (dry) moong dal to the pot. Dry roast (stir) the dal for 8-10 minutes until you see it darken a bit. It will change from pale yellow to slightly golden.
Add water and stir, then secure the lid, close the pressure valve and cook for 20 minutes at high pressure.
Quick release pressure and immediately add ghee, sugar, cardamom to the pot and mix well. Don’t panic if when you see the dal, it looks a bit dry - it will quickly absorb the ghee.
Once the dal absorbs the ghee, press the sauté button and stir continuously for 10 minutes, scraping the bottom of the pot regularly. This will be a bit of an arm workout.
Remove the steel liner from the instant pot (so the halwa doesn’t burn) and immediately scoop the halwa out into a serving bowl. When you pour it out, you’ll notice some ghee on the sides of the serving bowl - that means it separated a bit from the halwa and is perfect!
Garnish with crushed nuts and serve warm.