Meats should be very cold for a good finished product. Remove rind from bacon and line base and sides of a 22cm X 10cm terrine mould or loaf tin with slices in overlapping fashion. Allow slices to hang over edges so they can be folded over the top.
Minceveal, pork and chicken in a processor until smooth, add egg and process a furthur 30 seconds. Remove from processor and place in a large bowl. Process mixture in batches if necessary. Process onion and garlic and add to minced meats.
Refrigerate for 30 min until cold.
Stir in remaining ingredients, spread mixture into prepared tin and fold over bacon to cover the top.
Cover tin with foil and place in a baking dish with enough water to come half way up the sides of terrine (ie. in a bain marie). Cook in a moderate oven for 1 hour and a half.