Heat the oven to 200°C.
Season the beef thoroughly. Heat a heavy roasting tin on the hob and add a little oil. Sear the beef all over until you have a good colour, then brush with the mustard, especially the fat. Add the shallots and thyme to the roasting tin, then cook in the oven for 30 minutes.
Turn down the oven to 160C/fan 140C/gas 3. Keep cooking the beef for 15 minutes per 450g for medium-rare. Take out of the tin and rest for at least an hour under foil.
For the shallots, place them in a pan of hot, but not boiling, water. Poach for six minutes, or until soft. Then in a frying pan, add oil, thyme, salt, pepper and the shallots and cook for around 30 minutes or so.
Put the roasting tin on the hob, sprinkle in the flour and stir everything well. Add the wine, beef stock and redcurrant jelly and simmer until reduced by half. Strain into a jug and serve with the beef.
Recipe courtesy of Matt Tebbutt.