For the stuffing heat the butter in a heavy-based frying pan and fry the onions, bacon, mushrooms, garlic and Cumbrian ham for 3-4 minutes. Add the treacle vinegar. Cook until all the liquid has evaporated. Remove the pan from the heat and set aside to cool. Once the mixture has cooled add the chervil and season, to taste, with salt and freshly ground black pepper.
Remove the small fillet from the partridge (this is the fillet on the underside of the breasts) and make a small incision to the thicker side of the breast to form a small pouch.
Place the stuffing carefully into each pouch and fold the small fillet back over closing the pouch then wrap in the air dried ham.
Feed the bread, one slice at a time, through the pasta machine. Repeat the process several times until the bread is thin. Put the bread flat onto a board and brush with melted butter then sprinkle with dried sage and onion.
Place the seasoned stuffed partridge breast at the bottom of the bread, Fold in the sides of the bread and brush with melted butter, Fold the bread over to form a parcel and seal tight.
Preheat the oven to 180C/350F/Gas 4.
Heat the butter in a small frying pan and fry the partridge until golden-brown on all sides. (This may need to be done in batches.) Remove from the pan and cook in the oven for 6-8 minutes. Remove the partridge from the oven and set aside to rest for 2-3 minutes.
For the Madeira sauce heat the butter in a frying pan over a medium heat and fry the onions until softened and golden-brown. Pour in the Madeira and reduce the sauce by two-thirds.
Add the chicken stock and reduce the mixture to 300ml/10fl oz. Stir in the potato flour mixture and strain the sauce through a fine sieve and into a clean saucepan. Blend the sauce with a hand blender. Season to taste with salt and black pepper and stir in the pomegranate seeds.
For the crush, score the squash with a sharp knife. Rub with the garlic and drizzle over the olive oil. Season with salt and freshly ground black pepper. Bake in the oven for 30-40 minutes, or until tender. Remove the flesh and crush with the back of a fork. Set aside.
Prepare the sprouts by removing the outer leaves. Remove the base of the sprout, and then with a sharp knife make a cross on the base. Place into boiling water and cook for 3-4 minutes, then remove the sprouts and plunge them into iced water. Drain and reserve.
Heat the bacon fat in a frying pan and fry the chestnuts two minutes, or until golden-brown. Remove from the pan, place onto a piece of kitchen paper and set aside. Reheat the sprouts in a little butter, season with salt and freshly ground black pepper, and then add the chestnuts.
Divide the butternut crush among four plates. Trim the ends of the partridge blankets and place at the side of the butternut crush. Add the sprouts alongside and spoon over the sauce.