Prime Rib Delight with Rosemary, Dijon, and Mustard Infusion

Ingredients:

• 2 white onions, sliced to 1-inch (2.5 cm)
• ¼ cup Dijon mustard
• 1 prime rib (approximately 6 lbs/2.7 kg)
• 1 1/2 cups (375 ml) kosher salt
• 1/3 cup (75 mL) prepared horseradish
• 2 tbsp (30 ml) mustard seeds
• 2 tbsp (30 ml) fresh thyme
• 2 tbsp (30 ml) fresh rosemary
• 2 tbsp (30 ml) ground black pepper
• 5 crumbled bay leaves
• 3 egg whites

Methods:

1. Preheat the oven to 450°F (230°C).
2. Arrange onion slices at the bottom of a roasting pan and set aside.
3. Evenly coat the prime rib with Dijon mustard and set aside.
4. In a large bowl, combine salt, horseradish, mustard seeds, thyme, rosemary, pepper, and bay leaves. Add egg whites and stir until the mixture resembles wet sand.
5. Press the salt mixture evenly over the fat side and ends of the prime rib. Place the meat, bone side down, over the onions in the roasting pan.
6. Roast for 15 minutes, then reduce the oven temperature to 325°F (160°C). Continue cooking for 20 minutes per pound (450 g) or until an instant-read thermometer inserted into the thickest part of the roast reaches 130°F (55°C) for a perfect medium-rare doneness.
7. Transfer the rib roast to a cutting board and let it rest for 20 minutes. Remove and discard the salt crust before slicing the meat.
8. Indulge in the exquisite flavors of this Rosemary-Prime-Dijon Rib creation!