Place the quinoa and dal in a large bowl with water. Scrub well, refresh water and repeat the process 2-3 times until the water runs clear. Now soak this in enough fresh water such that it is completely immersed. Leave aside for 1 hour.
Drain the dal and quinoa. Transfer this to a 3-4 litre pressure pan. You can also make this on the stovetop in a pan with a lid or in the Instant Pot.
Add 4.5 cups of water + salt to the quinoa dal mix. The higher ratio of water is so that the cooked pongal has a porridge consistency. Pressure cook for 6-8 minutes. If I must explain the old fashioned way, reduce flame to lowest flame setting/ sim after one whistle and let it cook in this setting for 6-8 minutes. Switch off the flame and allow cooker to cool.
Meanwhile, prepare the tempering for the quinoa pongal.
In a small pan, heat the ghee. Fry the cashew nuts until golden brown. Remove this into a small cup with a slotted spoon. In the same ghee, fry all the remaining ingredients until the cumin splutters and curry leaves crisp up.
Open the cooker and using a ladle mash the quinoa dal mix to a smooth consistency. If it is dry, add remaining 1/2 cup hot water and bring to a simmer.
Transfer the fried cashews and prepared tempering over the pongal and stir to spread it uniformly. Ideally, this should be served immediately, otherwise it tends to clump up.
If you cannot serve this immediately, heat up portions with a few spoons of water, breaking up any clumps and serve.
Use any kind of millet instead of quinoa, using the same soaking, draining and cooking method.