Combine masoor dal and water in the instant pot. Add the onion, tomato, green chilies, turmeric, ground cumin, coriander and salt. Mix well. Lock the lid and cook on high pressure for 6 minutes.Let the pressure release naturally. Then open the lid and stir in coconut milk. If dal looks too thick, add more water and simmer until heated through on 'Sauté' mode.
½ cup Masoor Dal/ Red Lentils, 1½ cups Water, 1 Medium Onion, coarsely chopped, 1 Medium Tomato, coarsely chopped, 2~3 Green Chilies, slit, ¼ teaspoon Turmeric, ½ teaspoon Ground Cumin, ½ teaspoon Ground Coriander, To taste Salt, 1 cup Coconut Milk*