Remove the prime rib from its packaging and pat it thoroughly dry with paper towels. This is crucial for a good crust.

In a small bowl, whisk together the kosher salt, black pepper, garlic powder, onion powder, and dried thyme. Rub the entire roast with olive oil, then generously coat all sides with the seasoning mixture, pressing it into the meat.

Place the seasoned roast on a rack in a large roasting pan. Let it sit at room temperature for at least 2 hours, or up to 4 hours, before cooking. This helps the roast cook more evenly.

Preheat your oven to 250°F (120°C).

Insert an oven-safe, instant-read meat thermometer into the thickest part of the roast, avoiding bone.

Place the roasting pan in the preheated oven and cook until the internal temperature reaches your desired doneness (for medium-rare, aim for 120-125°F / 49-52°C). This will typically take 2.5 to 3.5 hours for an 8-10 lb roast. The reverse-sear method focuses on achieving the ideal internal temperature first, not a specific time. Check periodically, especially after 2 hours.

Once the roast reaches the desired internal temperature, remove it from the oven and transfer it to a cutting board. Tent it loosely with aluminum foil and let it rest for at least 30-45 minutes. DO NOT skip this step; it's essential for juiciness. During this rest, the temperature will rise another 5-10 degrees.

After the first rest, increase your oven temperature to 500°F (260°C). If you made Au Jus, keep the roasting pan with the drippings for later.

Return the roast to the hot oven (without the thermometer) and sear for 10-15 minutes, or until a beautiful, deep brown crust has formed on the exterior. Keep a close eye on it to prevent burning.

Remove the roast from the oven once seared. Tent it again loosely with foil and let it rest for another 15-20 minutes. This final rest allows the juices to redistribute throughout the meat, ensuring maximum tenderness and flavor.

Using a sharp carving knife, carefully separate the bones from the meat. Then, slice the prime rib into desired thickness against the grain.

While the roast is on its first rest, place the roasting pan (with drippings and any accumulated fat) over two stovetop burners set to medium-high heat. Add the red wine and scrape up any browned bits from the bottom of the pan with a wooden spoon.

Add the beef broth, fresh rosemary, and fresh thyme. Bring to a simmer and cook for 10-15 minutes, allowing it to reduce slightly and concentrate flavors. Strain the Au Jus through a fine-mesh sieve into a serving bowl, discarding the solids. Serve alongside the carved prime rib.