Beef Tenderloin with Parmesan Cream Sauce
For the beef tenderloin
5-6 lb whole beef tenderloin
4 Tbsp unsalted butter melted
2 Tbsp kosher salt
1 tsp freshly cracked black pepper plus more for serving
Flaky sea salt for serving
For the parmesan cream sauce
3 cups heavy whipping cream
3 cloves garlic peeled and smashed
3-4 sprigs tarragon
1 cup freshly grated Parmigiano Reggiano cheese
2 Tbsp parsley finely chopped
1 ½ tsp Dijon mustard
½ tsp kosher salt
¼ tsp freshly cracked black pepper
For the sautéed mushrooms, optional
2 Tbsp unsalted butter
5 oz baby shiitake mushrooms stems removed
1 medium shallot minced
½ tsp kosher salt
Recipe and Image provided by @WellSeasonedStudio
Cook the tenderloin
Allow beef tenderloin to sit at room temperature for 1 hour before cooking. Preheat oven to 275F then line a baking sheet with aluminum foil or parchment.
Place tenderloin on prepared baking sheet. Melt butter, then pour on top of tenderloin. Season on all sides with kosher salt and black pepper. Cook, undisturbed, in preheated oven for 1 hour 15 minutes, or until internal temperature of 130 F is reached (for medium rare). Begin checking temperature at 1 hour. To do this, place meat thermometer into end of tenderloin, inserting into the thickest part of the beef. Note that the temperature will continue to rise a bit as it rests.
Heat butter in a large skillet. Add mushrooms and cook undisturbed until browned and crispy, about 2-3 minuted per side. Add minced shallot, then season with kosher salt. Transfer to a bowl and set aside while you make the cream sauce.
Make the parmesan cream sauce
Place heavy cream in a large sauce pan, then add smashed garlic cloves and tarragon. Bring to a boil, then reduce until thickened, about 10-15 minutes. Cream will eventually bubble up, so make sure your pan is not too small. Use a slotted spoon to remove garlic and tarragon, then discard.
Add Parmigiano Reggiano, chopped parsley, Dijon, kosher salt, and black pepper, then stir to combine.
When ready to serve, slice tenderloin into pieces ¼" – ½" thick. Plate, then serve with parmesan cream sauce spooned on top (or on the side) along with sautéed mushrooms and shallots. Sprinkle the steak with flaky sea salt and black pepper just before serving.
Cooked beef tenderloin will last up to 5 days in a refrigerator. Store parmesan cream sauce separately.
Nutrition facts assume all of parmesan cream sauce will be consumed, but you will very likely have leftovers. Take that into account if looking at nutrition facts.