Whole Roasted Beef Tenderloin with Red-Wine Butter Sauce
- 1 cup dry red wine
- 1 cup red-wine vinegar
- 1 shallot, thinly sliced
- 2 tablespoons whole black peppercorns
- 2 sprigs fresh thyme
- 1 (5-pound) whole beef tenderloin, trimmed
- Fine sea salt and freshly ground black pepper
- 3 tablespoons canola oil
- 1 1/2 cups (3 sticks) cold unsalted butter, cut into pieces
Preheat oven to 400 degrees.
Place red wine, vinegar, shallot, peppercorns, and thyme in a small saucepan over high heat; cook until reduced to 1/2 cup, about 10 minutes. Remove from heat and set aside.
Generously season tenderloin on all sides with salt and pepper. Heat oil in a large heavy-bottomed roasting pan over high heat. Carefully add tenderloin and transfer roasting pan to oven. Roast, turning every 5 minutes, until medium-rare (120 degrees on an instant-read thermometer), 12 to 20 minutes.
Meanwhile, slowly whisk the cold butter into the warm wine reduction until emulsified. Strain through a fine mesh sieve into a small saucepan; season with salt and pepper and keep warm.
Remove tenderloin from oven and let stand for 5 minutes. Transfer to a cutting board and slice crosswise; arrange slices on a large platter. Pour any juices that have accumulated in the roasting pan into the red-wine sauce and stir to combine. Serve beef accompanied with sauce.