Heat gingelly oil in a earthernware pot.
Add fennel seeds and fenugreek. Let it sizzle.
Add in shallots and green chillies and mix well.
Add tomato puree and mix well. Cook till oil separates.
Add in all spice powders and mix well.
Add tamarind water, salt, water and mix well.
Simmer for 10 to 15 mins.
Add in fish pieces and simmer for 10 mins.