ingredients

• 1 (about 2 lbs) whole beef tenderloin
• 4 tablespoons grass fed butter divided
• 1/4 cup chopped scallions
• 2 tablespoons soy sauce 
• 1 teaspoon dijon mustard
• 1/4 teaspoon fresh cracked pepper

For the Horseradish cream sauce:

• 1/2 cup real mayonnaise
• 1/2 cup sour cream
• 1 tablespoon prepared horseradish
• 1 tablespoon lemon juice

cooking

1. Preheat oven to 400°F. Tie the beef tenderloin with butcher's twine and place the whole beef tenderloin in a low baking dish or cast-iron skillet. Spread 2 tablespoons of butter on top. Place in preheated oven and roast for 20 minutes. Do not open oven.
2. Meanwhile, in a small saucepan, cook the scallions in the remaining 2 tablespoons of butter. Add the soy sauce, dijon mustard and pepper and stir to combine. Add the sherry and heat until just boiling for 3-5 minutes.
3. After roasting for 20 minutes, open the oven and baste the beef tenderloin with the prepared sauce. Baste every 5 minutes for 20 more minutes, for a total cook time of 40 minutes.
4. Check internal temperature of the beef tenderloin before 40 minutes and remove from the oven when it reaches an internal temperature of 125°F. Transfer to a cutting board and create a tent with foil over top and let it rest for 15-20 minutes. The beef tenderloin temperature should rise to about 135°.
5. While it's resting, make the horseradish cream sauce. Whisk all the ingredients together until well combined. Refrigerate until ready to serve.
6. Cut into slices and serve with horseradish cream sauce.