Rinse foxtail millet and toor dal together until the water runs mostly clear. Soak in fresh water for 15 minutes, then drain well.
Saute in Instant Pot
Set Instant Pot to Saute. Heat oil or ghee. Add mustard seeds and let them pop.
Add cumin, fenugreek if using, dried red chili, curry leaves, hing, and green chili. Stir for a few seconds until fragrant.
Add onion and ginger if using. Saute 1 minute until the onion softens. Add tomato and mixed vegetables. Cook 1 to 2 minutes so the tomato softens slightly.
Stir in turmeric, sambar powder, salt, and jaggery. Pour in the tamarind extract and the drained millet-dal mix. Add 2 cups cooking water and stir, scraping the bottom so nothing sticks.
Pressure cook
Cancel Saute. Seal the lid and set valve to Sealing. Pressure Cook on High for 8 minutes.
Allow Natural Pressure Release for 10 to 12 minutes, then release any remaining pressure.
Open the lid and stir gently. The millet should mash lightly into the dal. If it looks too thick, add 1/4 to 1/2 cup hot water and simmer on Saute for 1 to 2 minutes. If it looks thin, Saute uncovered for a few minutes until it spoons thickly.
Finish with cilantro and a teaspoon of ghee or oil. Taste for salt and tang. Add a splash more tamarind water if you want sharper sourness.
Notes
Mistake + fix: if the millet stays firm after pressure cooking, it usually needed a longer soak or a little more water before sealing. Add hot water, stir, and cook another 2 minutes on High with a short natural release.Foxtail is the default. Little millet and barnyard millet use the same ratio. Quinoa also works in a pinch with the same Instant Pot time.For Jain / no onion no garlic: skip onion and ginger; rely on hing, curry leaves, and tomato.Store in an airtight container in the fridge for up to 3 days. It thickens when cold. Loosen with hot water when reheating.Freezes well for about 1 month in single portions.