1 - Pre heat oven to 150 ⁰c
2 - Marinate the beef in the red wine, garlic, shallots and thyme overnight. Strain the beef and reserve the wine. Separate the beef from the herbs and vegetables then season with salt and pepper and toss in the flour. Sear in batches in a heavy bottomed casserole dish.
3 - Colour the shallots and mushrooms in the casserole dish then add the wine with the herbs and garlic, reduce until syrupy then add the beef stock and browned beef. Cover with a lid and cook in the oven for around 3 hours or until tender.
4 - Allow to cool slightly and turn the oven to 180 ⁰c. For the bone marrow you can just pop one of the bones in the centre of the pie with a good pinch of salt and pepper and allow it to melt into the pie below. For this pie I have pushed the bone marrow out of the bones and diced it, season it with salt, pepper, finely diced shallot, parsley and a few capers and mixed it through the beef.
5 - Place the marrow bone in the centre of a 22cm pie dish and spoon the beef mixture around. Roll the puff pasty out to around 3mm thick ensuring that it is large enough to cover the pie. Cut a cross in the middle to make a hole for the bone then lay over the top of the pie and cut around the edge. Brush with the beaten egg then season with sea salt and black pepper. Bake the pie for 30-35 minutes or until a deep colour is achieved on the pastry.
6 – Serve with buttery mashed potato and fresh steamed green vegetables.