Bring chateaubriand to room temperature, pat dry with paper towels, and generously season with salt and pepper.
Preheat oven to 250 degrees F.
In a large cast iron pan/sauté pan lightly coat with olive oil and bring to high heat
Sear chateaubriand on all sides until nicely browned, about 2 to 3 minutes on each side.
Place chateaubriand on a roasting rack, or wire rack over a sheet pan; place in oven and refer to Omaha Steaks cooking chart for cook time and desired doneness. Use meat thermometer to ensure accurate cooking doneness.
Rest chateaubriand for 15 to 20 minutes, and then slice as desired.
Serve with mushrooms and Brussels sprouts