Soak the small yellow lentils (moong dal) in cold water for 15 minutes. Drain, rinse and set aside.
Press the sauté button. Add the oil, and allow it to heat up for a minute. Add the cumin seeds to the pot. Once they turn brown, add the garlic, ginger and Serrano pepper. Stir-fry for 30 seconds, then add the spices. Give everything a quick stir, then add the water and lentils.
Secure the lid, close the pressure valve and cook for 5 minutes at high pressure.
Naturally release pressure for 10 minutes. Open the valve to release any remaining pressure.
Stir in the garam masala and the spinach leaves. Once the leaves begin to wilt, garnish with cilantro and serve with a spoonful of ghee on top.