Peel and chop the marrow. Mix the turmeric, red chilli and salt into it and keep marinated for 15 minutes.
Add the thin coconut milk and green chillies and cook till the marrows are almost done.
Mix the rice flour into the thick coconut milk. Add to the curry and cook till the curry starts to thicken.
Add in the yogurt and cook for another minute. Switch off. Do not boil after adding the yogurt.
Heat oil in a saucepan. Fry the fenugreek seeds briefly.
Add the remaining ingredients and cook till the raw smell of garlic is gone. Pour into curry and close the lid. Leave for 10 minutes undisturbed. Mix and serve warm with rice!