Pick over the livers to remove and discard tough connecting tissue or blemished portions.Put liver in a bowl and add salt,pepper,bay leaf,thyme,allspice,cumin,cinnamon and cayenne. Heat chicken fat (butter) in heavy skillet over medium heat;add shallots and mushrooms.Cook stirring,until mushrooms give up their liquid.Cook until most of this liquid evaporeates.Add livers and seasonings.Cook,stirring occasionally about 10 minutes. Pour and scrape mixture into food processor or blender.Add cognac and blend to a fine puree.Spoon and scrape mixture into a small serving dish.Smooth the top.Serve slightly cooler than room temperature.Makes 4 to 6 servings.