Wash the liver thoroughly with cold water, place in a colander and allow the water to drain. Peel the onion and wash it
Place the prepared liver in a blender bowl and grind. Also chop the onion in a blender.
In a bowl, combine liver, salt, pepper, eggs and onion. Mix all ingredients thoroughly until smooth.
Prepare the mold, grease it with butter. Place the prepared mixture into the mold. Place the pan in an oven preheated to 180°C and bake for 50 minutes. Determine readiness by the appearance of the liver; it should darken. Pierce the casserole with a wooden skewer; it should come out clean.
Serve liver casserole hot or chilled as an appetizer or on its own. When serving portionwise, cut into diamonds, place on a plate and garnish with parsley and cranberries.