One large or two small eels are suitable for 4 persons.
Skin the eel, cut in pieces as long as a finger and put in boiling salt water with a top of parsley.
Use water enough to cover only half the fish, so the stock will be good and strong.
Cook the eel until it is tender and keep it hot while making the sauce.
Melt butter in a pot, brown a large onion and add flour and curry.
Dilute with the fish stock until the sauce is thick enough.
Taste it, and if it is not strong enough add more curry.
Pour it over the eel, serve in a deep dish and have an extra dish of fluffy steamed rice.