Green Hollandaise Sauce

Set into a saucepan five tablespoonfuls of flour, one tablespoonful of pepper corns, some thyme and bay leaves. Dilute this with a pint of water and boil while stirring so as to make a thick but smooth paste; cook it on a very slow fire for fifteen minutes, then take it off, let it get slightly cold, and add ten egg-yolks, afterward the butter and water, a very little at the time; using in all about two pounds of fresh butter and half a pound of ravigote butter, the juice of three lemons or simply a spoonful of vinegar; color with spinach green, and if too thick, thin it out with water, then strain through a tammy and keep it in a bain-marie at a moderate heat.