01 - Set the oven to 425°F and line a roasting pan with foil or parchment paper for easy cleanup.
02 - Pat the beef tenderloin dry with paper towels. Tie with kitchen twine if needed to ensure even cooking.
03 - Brush the tenderloin evenly with olive oil, then season with kosher salt and freshly ground black pepper. Place on a rack in the prepared roasting pan.
04 - Combine rosemary, thyme, parsley, garlic, Dijon mustard, coarse sea salt, and black pepper in a small bowl until a thick paste forms.
05 - Spread the herb paste evenly over the entire surface of the beef, pressing gently to adhere.
06 - Roast in the preheated oven for 30 to 35 minutes, or until a meat thermometer inserted into the thickest part reads 125°F for medium-rare or desired doneness.
07 - Remove from the oven and loosely cover with foil. Allow to rest for 15 minutes to retain juices.
08 - Cut into ½-inch thick slices and serve immediately.