Fish Stock for Lean Espagnole and Veloute Sauce

Butter the bottom of a sixteen-quart thick bottomed saucepan, and cover it with a layer of sliced onions, and on top of these four pounds of bony fish or else fish bones cut into pieces; moisten with one pint of water and set it on a brisk fire, covering the saucepan, and let it reduce to a glaze. Moisten again with one pint of white wine and four quarts of boiling water; skim off the fat and add a bunch of parsley garnished with two bay leaves, as much thyme, and half a pound of minced carrots and four ounces of celery, two cloves of garlic, and then let cook slowly for two hours; strain the whole through a fine sieve and use this stock for diluting the roux.