1. Preheat the oven to 450°. Line a roasting pan with aluminum foil. In a small bowl, combine the peppercorn mélange, Italian seasoning, sea salt, garlic powder and ground mustard. In another small bowl, add 2 teaspoons of the spice mixture and set aside for the gravy. Rub the remaining seasoning mixture all over the tenderloin and transfer the tenderloin to the aluminum foil-lined roasting pan, folding the thin end of the tenderloin under.

2. Place the pan in the oven and roast until the tenderloin is cooked to the desired doneness, 125° on an instant-read thermometer inserted into the thickest part of the roast for medium-rare, 40 to 50 minutes. Remove the pan from the oven and set aside to rest the roast for 15 minutes.

3. While the tenderloin rests, make the gravy: In a medium saucepan set over medium heat, add the butter and melt. Whisk in the flour and the reserved 2 teaspoons of the seasoning and cook, whisking constantly for 2 minutes. Add the beef stock a little at a time, whisking to smooth out any lumps until all of the stock is added. Bring the gravy to a boil, then reduce the heat to low and simmer until the gravy is thick, 5 to 10 minutes. Thinly slice the tenderloin crosswise and serve with the gravy.

Tip: Trimmed beef tenderloins are available for purchase in the supermarket meat case. If the beef tenderloin is untrimmed, ask the butcher to help you select and trim the meat so it yields a 5- to 6-pound beef tenderloin roast.