Roasted Chateaubriand

Ingredients: 

• 2 tablespoons extra-virgin olive oil
• 1 (10-ounce) center-cut beef tenderloin
• Kosher salt and freshly ground pepper to taste
• 5 cloves garlic, peeled and chopped
• 1 large onion, sliced
• 2 tablespoons unsalted butter, chilled
• 3 springs rosemary

Instructions:

1. Preheat oven to 450°F.
2. In an ovenproof, heavy-bottomed frying pan, heat the olive oil over high heat until hot but not smoking.
3. Season the meat with salt, garlic and pepper, then brown it in the pan on all sides.
4. Transfer the pan to the oven, place butter rosemary and onion and around the roast. Roast in the oven until the meat's internal temperature reaches 134°F (for medium), 25-30 minutes. Remove the pan from the oven.