Preheat the oven to 220°C (425°F). Pat the Rib Of Beef dry, tie if needed, rub all over with Vegetable Oil and season generously with Sea Salt and freshly ground Black Pepper.
Heat an ovenproof roasting pan until very hot, then sear the beef on all sides until deeply browned. Transfer the pan to the oven and roast at 220°C for 20 minutes to set the crust, then reduce the temperature to 180°C (350°F) and continue roasting until the internal temperature reaches your desired doneness (rough guide: 50°C/122°F rare, 57°C/135°F medium, 63°C/145°F well). Remove the beef, transfer to a board, tent loosely with foil and rest for 20–30 minutes; reserve the Pan Drippings in the roasting pan.
While the beef roasts, make the Yorkshire pudding batter: in a bowl whisk together the Eggs, Plain Flour and a pinch of Salt. Gradually whisk in the Whole Milk until the batter is smooth and slightly aerated. Let the batter rest at room temperature for 20–30 minutes.
Put a teaspoon (or a little more for extra crispiness) of Beef Dripping into each cup of a 12-hole muffin tin or into a large shallow roasting tin. Place the tin in the oven until the fat is smoking hot, about 5–10 minutes.
Carefully remove the hot tin from the oven and immediately pour the batter into the cups (about two-thirds full). Return to a very hot oven (220–230°C) and bake for 20–25 minutes without opening the door, until the puddings are deeply golden and well risen.
Make the gravy: put the roasting pan with the reserved juices on the hob over medium heat (or transfer juices to a pan). If needed, add a spoonful of fat, sprinkle in a couple of tablespoons of plain flour and cook, stirring, for 1–2 minutes to form a roux. Gradually whisk in the Beef Stock and any juices from the rested beef, scraping up the brown bits. Simmer until thickened, then season to taste with Salt and Black Pepper; strain if you prefer a smooth gravy.
Carve the rested beef thinly, spoon over the gravy and serve with the puffed Yorkshire puddings straight from the oven.
