Press the sauté button, add oil and allow it to heat up for a minute. Add mustard seeds, curry leaves and serrano pepper to the pot. Once the mustard seeds begin to pop, add the remaining ingredients to the pot.
Secure the lid, close the pressure valve and cook for 5 minutes at high pressure.
Naturally release pressure.
Adjust salt to taste and add more liquid if you’d like a thinner dal. The dal will thicken as it cools so if you are reheating it, you may need to add more broth.