Matelotta of tasty fish

1,500 Kg turbot or stingray
2 tablespoon of olive oil
30 g butter
4 onions
1 clove of garlic
1 carrot
Chopped parsley
A pinch basil
1 glass white dry wine
1 shot aged Grappa
1 tablespoon potato starch
Salt q.s.
Pepper q.s.

Mix salt, pepper, olive oil, onion, garlic, basil, carrot, parsley, wine and Grappa and add the deboned and chunked fish.
Pour the mixture into a preferably earthenware saucepan, cook for half an hour, turning the fish a few times with a wooden spoon.
After removing the fish from the saucepan, pass the sauce through a sieve and cook it for another five minutes.
Mix together the butter and flour, add to the sauce and stir.
Replace the fish in the saucepan for few minutes, cover it with the sauce and serve it hot in the saucepan.