Put the butter in a small saucepan, set it on the fire, and when melted, mix in it the flour; stir for one minute, add the carrot, stir now and then, and when nearly fried, add also the broth, claret wine, onion, garlic, cloves, bay-leaf, parsley, thyme, salt, and pepper; boil gently about one hour and forty minutes, and strain. If it boils away, add a little broth. Put it back on the fire with about half an ounce of butter, boil gently for about ten minutes, and it is ready for use.
This sauce is excellent with any kind of boiled fish, but especially with trout, pike, and pickerel.
A trout served with a genoise sauce is considered a recherche dish.