Preparation
- Preheat the oven to 190°C/170˚C fan. Prepare your beef by removing it from the fridge at least 2 hours prior to cooking to allow it to come up to room temperature.
- Prepare your gratin. Butter a 15 x 20cm ovenproof dish. Warm the cream and milk in a saucepan along with the thyme, garlic, and plenty of salt.
- Once the cream mixture starts to steam with heat, add in the sliced potatoes and cook just below simmer for 5 minutes.
- Tip the creamy potatoes into the prepared baking dish, sprinkle with parmesan and black pepper, and cover with foil. This will cook alongside the beef for a total of 1 hour.
- Sit the beef in a roasting tin and drizzle with the oil. Season well with salt and pepper.
- Add the beef and the gratin to the oven and roast the beef uncovered for 50 minutes - 1 hour then rest for 30 minutes. This should give you a nice pink meat. Roast for a further 30 mins if you like it well done. If you can, use a meat thermometer to check the temperature of your beef, 50°C for rare, 54°C for medium rare and 58°C for medium.
- Rest the beef for at least 20 minutes before carving.
- Remove the foil from the gratin for the final 20 minutes of cooking.
- Cook your Yorkshire puddings as per package instructions.
- Slice the beef and serve with the gratin, Yorkshire puddings, some gravy and lots of veg.