Roast Beef Tenderloin with Caramelized Onion and Mushroom Stuffing
Why This Recipe Works
For a recipe for stuffed beef tenderloin with a deeply charred crust, a tender, rosy-pink interior, and an intensely flavored stuffing that stayed neatly rolled in the meat, we chose the almost perfectly cylindrical Châteaubriand and used a "double-butterfly" procedure—making two cuts so the roast opened up into three parts (like a business letter). In this way the roast accommodated 50 percent more filling than a conventionally butterflied roast. We created a suitable crust for our tenderloin recipe in a shortened cooking time by coating the exterior of the roast with a layer of kosher salt an hour before searing, which allowed the salt to begin to break down the protein fibers in the outermost layer of meat, so that it browned quickly.