Mix together the beef, pork, streaky bacon, cloves, allspice ,lemon zest and the brandy. Stir well, tuck the bayleaves into the mixture, then cover and leave to marinate in the fridge for at least 6 hours or preferably overnight.
Melt the butter in a frying pan and add the garlic and onion. Cook over a low heat for 10 minutes, then add the mushrooms and cook for a further 10 minutes, until they are softened and the liquid from the mushrooms has evaporated. Stir in the parsley and leave to cool.
Remove the bay leaves from the marinated meat. Add the cold mushroom mixture to the raw meat, season well and mix together thoroughly.
Preheat the oven to 200⁰C - Gas6. Roll out the pastry on a lightly floured surface into a 38cm square, trim the edges and keep for decoration. Pile the meat mixture into the middle of the pastry, shaping it into a rectangle about 30cm long. Brush the edges of the pastry with a little beaten egg. Fold the pastry over the meat as if you were wrapping a parcel. Place on a baking tray seam- side down.
Decorate the parcels with shapes cut from the pastry scraps and brush all over with beaten egg. Cook on the middle shelf of the oven for 15 minutes, then lower the temperature to 180⁰C Gas 4 and cook to 1 ¼ hours, or until the filling is cooked and the pastry golden brown.
Cool completely before serving in slices.