Heat the butter and oil in a flameproof casserole or a saucepan and fry the rabbit portions until golden brown, then transfer them to a plate. Add the bacon to the casserole or pan and fry gently until it begins to release its fat. Stir in the onion and cook for 5 minutes, or until it softens and begins to brown. Stir in the flour and cook for 1 minute, then gradually stir in the cider.
Return the rabbit portions to the pan, add the prunes and bouquet garni and season to taste with salt and pepper. Bring to the boil, then reduce the heat, cover and simmer for 1 hour, or until the rabbit is very tender. Remove the pan from the heat and allow to cool. Chill overnight in the refrigerator.
Next day, preheat the oven to 200°C. To make the pastry, mix the flour with the suet, grated butter, lemon rind and parsley and make a well in the centre. Make the lemon juice up to 3/4 cup with cold water and stir in the beaten egg. Pour into the well in the centre of the flour and mix together to make a soft dough. Knead the dough on a lightly floured surface for 1 minute, or until smooth.
Transfer the cold rabbit stew to a large, deep pie dish. Roll out the dough to an oval 5 cm larger than the dish and cut off a strip 2–3 cm wide from around the edge. Wet the edge of the pie dish and press the strip firmly onto it. Brush the strip with milk, then cover the pie with the remaining dough. Press the pastry edges together well to seal, then trim off the excess dough and decorate the edge.
Make a hole in the centre of the pie to let the steam escape. Brush the top with the milk to glaze, then bake in the centre of the oven for 45 minutes, or until the pastry is risen and golden brown. If the pie begins to brown too much, cover it loosely with a piece of foil.