Preheat the oven to 400 degrees F.
To make the Yorkshire Pudding batter, in a bowl, combine the flour and salt. In another bowl, beat the eggs. Add the milk and gradually add to the flour, mixing to make a thin, smooth batter, being careful not to over mix. Let rest for at least 1 hour at room temperature, or for several hours in the refrigerator (bringing to room temperature before cooking).
Put the roast in a small roasting pan, bone side down. With a small sharp knife, make sixteen 1/2-inch-deep slits in the meaty side of the roast. Insert 1 garlic clove into each slit, pressing into the meat. Pinch with your thumb and index finger to close the openings.
Combine the chopped thyme, salt, Essence, and pepper in a small bowl. Slowly stir in the oil to make a paste. Rub the paste on both sides of the roast, and place the thyme sprigs under the roast.
Roast for 1 hour. Remove the pan from the oven and turn the roast for even browning. Reduce the oven temperature to 350 degrees F and continue roasting until an instant-read thermometer inserted in the thickest part of the roast reads 125 to 130 degrees F for medium-rare, about 45 minutes, or 140 degrees F for medium, about 1 hour. Remove from the oven and let the roast stand for 15 minutes before carving.
While the roast is resting, make the Yorkshire Pudding in the same roasting pan.
Increase the oven temperature to 450 degrees F. Pour off all but 3 tablespoons of the hot pan drippings, adding hot melted butter as necessary to make the correct measure. Place the pan in the oven to stay hot while the oven comes to temperature.
Pour the prepared batter into the dish and bake, without opening the oven door, until risen and golden brown, 15 to 20 minutes. Remove from the oven and serve immediately with the carved rib roast.
Yield: 6 servings