Combine rinsed moong, turmeric, and 2 cups water in a pressure cooker. Cook for 2 to 3 whistles (or simmer covered 15 to 18 minutes) until the dal is soft and mashable.
Grind coconut, cumin seeds, and green chili with 2 to 3 tbsp water to a coarse paste.
Stir the paste and salt into the dal. Simmer 3 to 4 minutes, adding a splash of water if it is too thick. It should pour easily off a spoon.
Optional: heat coconut oil, pop mustard seeds and curry leaves, and pour over the dal.
Millets
Bring rinsed foxtail millet, 2 cups water, and salt to a boil. Cover, reduce heat to low, and cook 12 to 15 minutes until water is absorbed.
Rest covered 5 minutes. Fluff with a fork and let steam escape for 1 minute.
Ghee tempering
Heat ghee in a small pan. Add mustard seeds and let them pop fully.
Add cumin if using, curry leaves, dry red chili, and hing. Fry a few seconds until fragrant.
Pour over the fluffed millet and fold gently until the grains look lightly glossed.
Serve millets in bowls with parippu ladled over or beside them.
Notes
Soft dal first: if moong still feels chalky, cook longer before adding coconut paste.Fluffy millet cue: grains should separate after resting; if sticky, use a little less water next time.Vegan: use coconut oil for the millet tempering and skip ghee on the dal.Make-ahead: refrigerate dal and millets separately up to 3 days. Reheat millets with a sprinkle of water, then refresh with a quick new tempering if you like.This is not khichdi: keep the pots separate so textures stay distinct.