Cut all the vegetables lengthwise into long strips. (The shape matters!)
Cook all the vegetables in a pressure cooker with turmeric powder, slit green chillies, salt, curry leaves; no water required. Cook for 1 whistle or 5 minutes, whichever happens first. If you do not have a pressure cooker, then cook in a regular pot; add just enough water to cook the vegetables.
Grind coconut and cumin seeds with a bit of water to a fine paste and add to the boiled vegetables.
Add enough curd to this, stirred through to get a creamy consistency.
Prepare tadka or tempering by heating coconut oil and curry leaves. Switch off the flame and add a few drops of water to this and then pour over the dish. There will be some spluttering so make sure the flame is off.