Marinate the hare and rabbit in the brandy and Port in a small bowl for 24 hours. Keep refrigerated and covered.
Heat the butter in a frying pan and sauté the livers for 4–5 minutes, or until the inside is pink but not bloody. Remove from the pan and cut into small pieces.
Mix the pigeon, pheasant, parsley, caramelised onion, pancetta, liver, rabbit and hare together in a large bowl. Season with salt and add the thyme leaves and juniper berries. Cover and leave in the fridge for up to 2 hours.
Preheat the oven to 200C/180C Fan/Gas 6. Line two baking trays with baking paper.
Cut the pastry sheet into 8 x 12cm/4½in circles. Divide the rabbit filling into four and place each portion in the centre of four pastry circles. Brush the egg around the edge of the four pastry circles and place another pastry circle on top. Gently push the edges together. Brush the top of the pithiviers with egg and score the top of the lid to release excess steam.
Place the pithiviers on the baking trays and bake for 20–25 minutes, or until golden.
Mix together all of the salad ingredients in a salad bowl. Serve with the pithiviers.