Place a wok on flame. Add peper,fennel,fenugreek and roast in low flame .To it add chillipowder,coriander powder and grind it to fine paste.
Pour oil in another wok, add mustard seeds to it, dry chilli, small onion, sauté well. Now add the tamarind paste and the finely ground paste to it and cook well .Add water to make it thick consistent .Let the above to cook well with closed lid.
Now add the tuna fish to the above and let it cook well. When cooked remove from flame by adding coconut milk(don’t cook with coconutmilk,just add the milk and remove immediately