Melt the butter in a skillet. Add the onions and fry until they are turning golden. At this point add the liver which has benn sliced into thin strips and cook for 10 minutes & remove form heat. Mix all of the ingredients with the onions and liver in a food processor. Chop in processor until a smooth textured mixture is achieved. Grease a 23 cm baking dish and spoon the mixture into it. Bake for 45 minutes in a pre-hetaed 230ºC oven. Remove from oven and cool to room temperature. Note: This mixture may be turned into metal molds for baking or into individual custard cups as well.