Slowly melt the chocolate in the water, bring to a gentle boil, remove from the fire, and add the yolks, beating with a spatula, then replace on a low fire to poach the eggs in the chocolate. Do not stop beating. Remove from the fire and add the butter and the praline paste. Let cool, beating from time to time (this cooling takes a rather long time). When the mixture begins to solidify, take some with a spoon, place it in some grated chocolate (prepared in advance), and shape to resemble real truffles. These truffles keep a week. To keep a longer time, substitute vegetable shortening for the butter. Source : The Art of French Cooking Posted by: Rina de Jong