Whole roasted beef tenderloin is a once-a-year celebratory dish that is just absolutely fantastic. It’s not cheap, hence why most people do it once a year when celebrating, but BOY-OH-BOY is it good. And this Roast Beef Tenderloin with Creamy Horseradish Sauce — SO good.
I was very intimidated by roasting my first beef tenderloin–because if I failed, that was a big chunk of money right down the drain. But honestly, it turned out perfectly medium-rare, juicy, flavorful and the horseradish sauce to top it all off? YES PLEASE.
I will say, one trick to really getting the perfect roast tenderloin is this gadget here— a thermometer with a cord so that you can monitor the exact temperature of your roast during the entire cooking process. No need to open the oven and check the temperature. This guy saved me. With the long 40″ cable length, you can have the probe inserted into the roast during the cooking process, and the base of the thermometer is outside of the oven so you can read it and track the temperature at all times. I love this gadget for roasting turkey, chicken and other large cuts meat like brisket.
For this roast beef tenderloin, when the beef registers 120 to 125 degrees (for medium-rare/rare), you pull it from the oven, cover with foil and let rest for 10-15 minutes before slicing to ensure the juices really lock-in, then slice and serve with a delicious, whole30 approved creamy horseradish sauce. YUM.
So don’t be intimidated by this beautiful cut of meat, and get to cooking this Roast Beef Tenderloin with Creamy Horseradish Sauce! Your family will think you are oh-so-fancy!
- 3.5-4 lb. Beef Tenderloin
- 3-4 tbsp. olive oil
- kosher salt
- coarse black pepper
- 2 cloves garlic, minced
- 1 sprig rosemary leaves, finely chopped
- Kitchen Twine
- 1 cup homemade mayo
- 4 tbsp. freshly grated horseradish
- 2 tsp. distilled white vinegar
- the juice of 1 lemon
- salt, to taste
- In a bowl, combine all of the ingredients for the horseradish sauce. Stir to combine. Refrigerate until ready to serve.
- Remove the beef tenderloin from the fridge to let get to (or as close to) room temperature as possible before cooking-- about 1-1.5 hours before baking.
- Preheat oven to 425.
- Using Kitchen Twine, tie off any loose pieces (so that it cooks evenly).
- Drizzle and rub the tenderloin all over with olive oil so that it is coated evenly.
- Season generously with kosher salt and coarse black pepper.
- Now, sprinkle with the chopped rosemary and garlic. Using clean hands, rub all over the tenderloin so that the salt, pepper, rosemary and garlic is evenly distributed all over.
- Insert a meat thermometer and place in the oven until the beef registers 120 to 125 degrees F for medium-rare/rare. Beef will probably cook in 20 to 25 minutes depending on its temp before it goes in the oven.
- When meat is done, remove from oven. Cover the meat loosely with foil and allow to rest for 10 minutes before slicing.
- Slice, and serve with horseradish sauce.