1: Take the beef sirloin out of the fridge at least 30 minutes before you want to start cooking. Preheat the oven to 200°C/Fan 180°C/Gas 6.

2: Remove the string from the rolled sirloin and score the fat heavily with a sharp knife – this will help the fat render when you sear the joint in the pan. Tie the rolled sirloin with new string to secure it. Season all sides of the sirloin liberally with salt and pepper.

3: Place a large heavy-based non-stick frying pan over a medium heat and lift the rolled sirloin into the pan, placing it fat side down. Sear for 15–18 minutes, turning as necessary, until the fat is well rendered and the joint of beef has a golden-brown crust all over.

4: Meanwhile, place the baby carrots and beets in a large roasting tray. Drizzle with the olive oil and scatter over the thyme sprigs. Season well with salt and pepper and toss together well.

5: Lift the sirloin out of the pan and sit it on a rack over the roasting tray of veg. Save 4 tbsp of the rendered beef fat in the frying pan for the dressing.

6: Place the roasting tray on the middle shelf of the oven and roast for 35–45 minutes or until the meat has an internal core temperature of 42–45°C (check with a digital probe thermometer).

7: Remove the roasting tray from the oven and transfer the beef joint to a warmed serving platter. Leave it to rest in a warm place for around 20 minutes (it will continue to cook as it rests).

8: Return the roasting tray to the oven to continue cooking the veg while the meat rests. (In total, the veg will cook for55–60 minutes.)9.Once the beef is rested, prepare the beef fat dressing. Strain the reserved beef fat into a small pan and warm through. Whisk in the wine vinegar and Dijon mustard and taste for seasoning, adding salt and pepper if needed. Stir through the chopped parsley.

9: Carve the sirloin and serve with the roasted baby carrots and summer beets, with the warm dressing spooned over.