Emeril Lagasse's Horseradish-Crusted Tenderloin of Beef with Port Wine Reduction

To prepare beef: Preheat the oven to 400 degrees F. Rub the tenderloin with the oil and Emeril's Original Essence. Heat a sauté pan large enough to hold the tenderloin over high heat until the pan is very hot, about 2 minutes. Sear the meat until evenly browned on all sides, about 2 minutes per side. Remove from the heat. Line a shallow baking pan fitted with a wire rack with aluminum foil. Place the tenderloin on the rack. Rub the top and sides of the meat with the mustard. Combine the horseradish, black pepper, garlic, and salt in a small mixing bowl. Using your hands, press the horseradish mixture over the mustard on the top and sides of the tenderloin. Roast the tenderloin for about 30 minutes for rare (120 to 125 degrees F on an instant meat thermometer) and about 35 minutes for medium-rare (130 to 140 degrees F on an instant meat thermometer). Remove from the oven and rest for 5 minutes before slicing. Drizzle the beef with the wine reduction if desired. To prepare port wine reduction: Combine all of the ingredients in a medium-size saucepan over medium heat and bring to a boil. Continue to boil the mixture until it thickens and reduces to about 1/2 cup, about 30 minutes. Strain through a fine-mesh strainer and let cool. Use at room temperature.