1kg centre-cut beef fillet, tied with kitchen string at 2cm intervals
12 French shallots, peeled
1½ tbsp olive oil
Salt flakes and freshly ground
½ bunch thyme (4–5 sprigs)
25 g butter
3 tbsp caster sugar
3 tbsp balsamic vinegar
150ml beef or chicken stock
Small handful of chives, finely snipped
Take the meat out of the fridge 1½ hours before cooking. This is important for an even cook.
Preheat the oven to 210°C.
Bring a saucepan of water to the boil. Add the shallots, bring back to the boil and cook for 2 minutes. Drain, allowing the steam to subside to ensure they dry out a little.
Place a large frying pan over high heat. Rub 1 tablespoon of the oil over the beef and season generously with salt and pepper. Sear the beef all over for 5–6 minutes until a deep brown crust forms.
Place the thyme in the centre of a roasting tin and rest the beef on top.
In the same frying pan, melt the butter with the remaining oil over medium heat and, when frothy, add the shallots and sugar and cook for 8–10 minutes, tossing three or four times to ensure the shallots colour uniformly. Add the balsamic vinegar and let it bubble away for 30 seconds. Pour into the tin around the beef. Roast for 15–20 minutes.
If you have a meat thermometer handy, the internal temperature of the beef should be 55°C for rare. Cook for an extra 5–6 minutes if you prefer medium–rare and a little longer for medium.
Remove the beef from the tin and place on a plate. Cover loosely with foil and rest for 15 minutes.
Place the tin over medium–high heat and add the stock. Using a wooden spoon, detach any shallots stuck to the base, ensuring they stay whole, and simmer for 8–10 minutes until the juices have thickened. Discard the thyme.
Slice the beef into 1cm thick medallions and arrange on a platter. Pour over the juices from the tin and spoon the sticky shallots around the meat. Serve with the chives and an extra pinch of salt.