Preheat the oven to 220ºC.
Pat the beef dry with a paper towel, coat with a little oil and season with salt and pepper. Heat a large frying pan over a high heat and when the pan is very hot, sear the meat until browned all over. Transfer to a roasting dish (bone side down) and roast in the oven for 15 minutes. After 15 minutes, reduce the oven temperature to 160°C and continue to cook for 20 minutes per 500g for medium (or 15 minutes per 500g for rare). Remove from the oven, cover loosely with foil and rest for 20-30 minutes before carving across the grain.
Shake the shallots with the cornflour in a small bag to coat. Heat the oil in a small saucepan over a medium-high heat. Add the shallots and cook for 5-10 minutes until they are golden brown and crispy, stirring occasionally. Drain on paper towels and sprinkle with a pinch of salt.
While the meat is cooking, place the potatoes in a pot of cold salted water. Bring to the boil, then immediately reduce to a gentle simmer and cook until the potatoes are tender. Drain, then place back over a low heat for a minute or so to dry out any remaining moisture. Mash the potatoes or pass through a potato ricer or sieve. Stir in the butter and cheese using a wooden spoon then add chives. Season if required.
To make the jus, discard any excess fat from the roasting dish, place the dish on the stovetop over a medium-high heat, add the red wine and bring to the boil for 30 seconds. Reduce the heat and simmer until reduced by two thirds, scraping the bottom to add flavour. Add the stock and simmer for another few minutes. Whisk through the butter and sugar and pour into a jug.