Put the venison, liver, onion, garlic, juniper, allspice and brandy in a bowl and stir to mix. Cover and marinate overnight in the refrigerator.
Heat the oven to 160°C (325°F, gas mark 3). Roughly chop 2 rashers of bacon and put in a food processor or blender with the marinated ingredients, the egg and some salt and pepper. Process until smooth.
Stretch the remaining bacon rashers with the back of a knife, then use them to line a 1 litre (1¾ pint) loaf tin or terrine dish, overhanging the edges. Spoon in the meat mixture and fold the bacon over to cover.
Cover with foil and transfer to a roasting tin. Add water to come halfway up the sides and cook in the oven for 2 hours. Remove from the roasting tin and place a heavy weight or cans of food on top. Leave to cool.
Remove the weight, turn the terrine out onto a plate. Slice and serve with redcurrant jelly, mixed salad and crusty bread.
Pheasant breast or diced rabbit can be substituted for the venison meat.