Herb-Crusted Prime Rib

Combine onion, 1/4 cup plus 1 teaspoon garlic, vegetable oil, beef base, fresh rosemary, 1/4 tablespoon plus 1/4 teaspoon ground rosemary, and black pepper together in an electric blender. Blend on low speed for 30 seconds to 1 minute. Blend on high speed until completely emulsified and mixture takes on a slightly lighter color, 3 to 5 minutes. Pour into a storage container and refrigerate until set, 8 hours to overnight.

Preheat the oven to 450 degrees F (230 degrees C).

Combine kosher salt and pepper in a large bowl. Mix completely.

Blot excess moisture from the meat and place onto a sheet pan. Season entire prime rib with about 1/4 cup seasoning mixture; reserve remaining mixture for another use. Place rib upside-down and coat the bottom with 1/4 cup of wet rub mixture; flip and coat the back and ends with another 1/4 cup wet rub. Coat the top with 1/4 cup wet rub to ensure a smooth, thick coating; reserve any remaining wet rub for another use.

Sear in the preheated oven until crust is dark golden brown with dark spots, 15 to 30 minutes. Do not let the internal temperature exceed 57 degrees F (14 degrees C) while searing. Reduce oven temperature to 250 degrees F (120 degrees C); open the oven to vent heat from searing process.

Place a wire rack onto another sheet pan and transfer the rib roast to the new pan. Return the rib to the oven with an internal thermometer inserted into the middle of the rib facing the oven window, or use a remote thermometer.

Roast the rib in the preheated oven until the internal temperature is about 10 degrees less than desired doneness, 3 1/2 to 4 1/2 hours. An internal temperature between 130 and 135 degrees F (55 to 57 C) is good for medium-rare, so remove at 120 to 125 degrees F (49 to 52 C).

Turn the oven temperature as low as it will go; open the door to vent heat and humidity for about 5 minutes. Close the door and let roast sit in the oven for at least 1 hour more.

Transfer rib to a cutting board and let rest for 5 to 10 minutes; slice using a very sharp or electric knife and serve.