Bring Beef to room temp: Take beef out of the fridge 2 - 3 hours before cooking to bring to room temp (key tip for even cooking). Pat dry with paper towel.

Preheat oven to 240°C/460°F (220°C fan). Adjust shelf so beef will be sitting in the middle of the oven.

Garlic Herb Butter: Mix together.

Roasting bed: Place onion, garlic and herbs in a heavy based oven proof skillet (or use a roasting pan).

Slather 1: Spread a thin layer of butter on the underside of the beef (ie the bone side). Place beef on onion etc, butter side down. Spread about ⅔ of the butter on the top and sides (reserve some for Slather 2).

Hot oven: Roast 20 minutes.

Slather 2: Remove, spread over remaining butter. Turn oven down to 120°C/250°F (100°C fan).

Slow roast: Roast for a further 1 ½ hours, basting every 30 minutes with the juices in the pan, until the internal temperature is 51°C / 123.8°F in the centre (for medium rare, Note 4). Start checking the internal temp early.

Rest: Transfer beef to plate. Cover loosely with foil and rest for 20 - 30 minutes. Internal temperature will rise to 56-58°C / 133-136.4°F (which is medium rare).

Slice beef and serve with Sauce! For a classic high-end Steakhouse experience, serve with Paris Mash and Garlic Sautéed Spinach.

Place skillet with onion and garlic left in it on the stove over high heat. Add wine and beef stock, rapidly simmer for 10 minutes until it reduces by ⅔ or so, down to 1 ½ cups or liquid.

Lower heat to medium. Mix cornflour with 2 tbsp water. Drizzle in half and stir. Sauce will thicken in 1 minute or so. Add more cornflour water mixture if you want it thicker.

Strain into bowl, pour into sauce jug.