• Remove the chateaubriand from the refrigerator one hour ahead of time. This step takes the chill off for more even cooking with juicier meat.
• Preheat the oven to 400°F, placing the oven rack in the upper middle position. Fit a small roasting pan with a wire rack and set aside.
• Pat dry the meat with paper towels to remove excess moisture. Then rub on all sides with oil followed by the salt and pepper.
• Optional: If your oven is not powerful, you may wish to pan-sear the chateaubriand first. Place a skillet over medium-high heat for 3-5 minutes until hot. Then add the beef and sear for one minute per side until nicely browned all over. Use kitchen tongs to move it easily.
• Place the beef in the preheated oven to roast for 15-30 minutes depending on size and your desired doneness. Start checking doneness after 15 minutes by inserting an instant-read thermometer into the center: 115°F is rare, 125°F is medium-rare and 135°F is medium (see note).
• Once the meat has reached your desired doneness, remove from the oven to a carving board. Cover tightly with foil to keep warm and let it rest for 5-10 minutes so the juices can retreat back into the meat. During this time you can make the optional sauce below.

Chateaubriand Sauce (Optional)

• Place a skillet on medium heat. Add the minced shallot and butter, sautéing for several minutes until translucent.
• Add the red wine and boil for several minutes until thickened slightly.
• Add the demi glace and continue boiling until the sauce is thick enough to coat the back of a spoon.
• Swirl in the remaining tablespoon of butter and add the fresh herbs.
• Remove from the heat. Slice the chateaubriand and drizzle or spoon the sauce on top. Serve immediately.