I love this recipe because it's luxurious but also economical since one tenderloin can feed a crowd. It's also so easy to execute a perfectly cooked piece of meat with the reverse-sear method. You can always split the tenderloin in half and cook one portion to a higher temperature so you can offer up more well-done pieces of meat.
Equipment needed: A good instant-read thermometer
For the black powder rub:
In a dry pan, toast all sesame seeds, poppy seeds, peppercorns and mustard seeds for about 3 to 4 minutes or until fragrant. Place in small food processor, blender or spice grinder along with the salt, brown sugar, onion and granulated garlic, and pulse until finely ground.
For the horseradish-cheddar cheese sauce:
Set a medium saucepan to low heat. Add in evaporated milk, hot sauce and Dijon, and whisk together until uniform and smooth. Toss grated cheese and cornstarch together in a bowl until totally coated. Whisk in cheese and horseradish. and heat, stirring constantly, for about 5 minutes, until all the cheese is melted and the sauce is silky and smooth. Season to taste with kosher salt.
For the beef tenderloin:1.
Set an oven rack in the middle position and preheat oven to 225 F.2.
Rub the entire tenderloin with the black powder rub and pepper. If you can, rest on a wire rack on a sheet pan in the fridge overnight to help really intensify the flavor.3.
Roast until internal temperature of the center of roast registers 125 F for and ideal medium-rare, about 2 to 3 hours. If you want it more well done, aim for 135 F internal temp.4.
Heat a large cast-iron skillet over high heat. Add oil then the tenderloin on the first side for about 45 seconds. Add butter, garlic and thyme, and flip the tenderloin, basting with the melted butter the whole time. You're done once all sides and edges are brown, about 2 to 4 minutes of searing total.
Cut into beautiful medallions and remember to remove the twine. Serve immediately as there is no need to rest the meat with the reverse-sear method. Serve with horseradish-cheddar cheese sauce.