Season the beef cheeks with salt and black pepper, cover and store in the fridge for 24 hours.
Place a heavy frying pan on a high heat, heat the vegetable oil and add the beef cheeks. Sear on all sides, then place in a casserole dish.
In the same pan, fry the vegetables and garlic on a medium heat until they begin to caramelise. Pour in the wine and Madeira and reduce by half. Then, add the beef stock and passata. Bring the liquid to the boil, removing any scum that rises to the top.
Add the juniper berries, bay leaves, thyme, anchovies, ceps and two walnuts. Cover with a lid or aluminium foil, and cook in the oven for 2-2½ hours, until the meat is very tender. Take out of the oven, then remove the beef from the pan and place it on a tray. Cover with foil and ensure it remains warm.
Strain the remaining liquid into a clean pan and heat. Reduce to thicken until it reaches a sauce consistency and is flavourful. Keep the sauce warm until ready to serve.
To prepare the glazed carrots, place the carrots in a shallow pan, so that they are not covering each other, add the butter, a little salt and sufficient carrot juice to cover. Put a lid on the pan and bring to the boil. Cook until the carrots are tender, adding small amounts of water where necessary. Remove the lid immediately after the carrots are cooked. Reduce the liquid reduce until it is thick enough to glaze the carrots. Add a squeeze of lemon juice to taste.
To cook the mash, slice the potatoes into even sized pieces. Place in a saucepan filled with the right amount of cold water to cover the potatoes and add a good pinch of salt. Bring to the boil, then reduce to a simmer until the potatoes are tender, approximately 20 minutes.
Drain and return to the pan, turn down the heat and dry fry for a few minutes on all sides. Mash the potatoes. Mix in the milk, butter and cream (to your preferred consistency), while the potatoes are still hot. Add salt if required.
Place equal portions of the beef cheek, carrots and mash on four serving plates. Add the remainder of the walnuts and chopped parsley to the warmed sauce just before serving. Spoon the sauce over the beef and serve.