Step 1: Prepare the Roast

1. Bring to Room Temperature: Remove the prime rib from the refrigerator and let it sit at room temperature for about 1 hour before cooking.

Step 2: Preheat the Oven

1. Preheat Oven: Preheat your oven to 450°F (230°C).

Step 3: Season the Roast

1. Mix Seasoning: In a small bowl, combine minced garlic, olive oil, kosher salt, black pepper, rosemary, thyme, and Dijon mustard (if using).
2. Rub the Roast: Pat the prime rib dry with paper towels. Rub the seasoning mixture all over the roast, ensuring it is well coated.

Step 4: Roast the Prime Rib

1. Initial High Heat: Place the seasoned prime rib in a roasting pan, bone side down. Roast in the preheated oven for 20 minutes.
2. Lower the Temperature: After 20 minutes, reduce the oven temperature to 325°F (165°C) and continue roasting. Use a meat thermometer to check for doneness:
   

• Rare: 120°F (49°C)
• Medium Rare: 130°F (54°C)
• Medium: 140°F (60°C)
• Medium Well: 150°F (66°C)
• Well Done: 160°F (71°C)

Step 5: Rest the Roast

1. Remove and Rest: Once the desired temperature is reached, remove the prime rib from the oven and cover it loosely with aluminum foil. Let it rest for at least 20-30 minutes. This allows the juices to redistribute, ensuring a juicy roast.

Step 6: Prepare the Au Jus (Optional)

1. Make Au Jus: While the roast is resting, place the roasting pan on the stovetop over medium heat. Add beef broth and red wine (if using) to the pan, scraping up any browned bits. Bring to a simmer.
2. Thicken (Optional): If you prefer a thicker sauce, stir in the cornstarch mixture and cook until thickened.

Step 7: Carve and Serve

1. Carve the Roast: After resting, carve the prime rib into slices. Serve with au jus on the side and enjoy!