Heat the oil in a pan over medium heat. Add mustard seeds and let them pop fully.
Add urad dal if using and fry until light golden. Stir in curry leaves, green chili, hing, and onion if using. Saute until the onion softens, about 1 minute.
Way 1: Beans
Add beans, turmeric, and salt. Toss to coat.
Splash in 2 to 3 tbsp water, cover, and cook 3 to 4 minutes until the beans are tender-crisp and still bright green.
Uncover and cook off any leftover moisture. Stir in grated coconut (and crushed cumin if using) for 30 to 60 seconds. Taste for salt and serve.
Way 2: Carrot
Add carrots, turmeric, and salt. Toss well.
Cook uncovered 4 to 6 minutes, stirring often, until tender-crisp and most moisture has evaporated. Do not let the carrots go mushy.
Stir in grated coconut for 30 to 60 seconds. Finish with lemon juice if you like. Taste for salt and serve.
Notes
Use only 1 to 2 tbsp coconut for a light finish; add another spoonful only if you miss the classic sadya-style richness.Cut beans thin so they cook evenly. Thick pieces stay raw in the center.For Jain / no onion no garlic: skip onion and rely on hing, curry leaves, and chili.Store leftovers in an airtight container in the fridge for up to 3 days. Reheat in a dry pan so the coconut does not turn soggy in the microwave.