What is Chateaubriand, exactly?

It is a center-cut piece of the beef tenderloin, the long muscle that runs under the loin. The tenderloin is the most tender muscle on the animal, and the center cut is the thickest, most uniform part.

How many people does a 2 lb roast serve?

About four to five. Tenderloin is lean and boneless, so plan roughly half a pound per person, a little less if there are many sides.

How should I cook a tenderloin roast?

Roast it hot and briefly, or sear it and finish it in the oven, and pull it at medium-rare. Because it is lean, it dries out past medium, so use a meat thermometer and rest it before slicing.

Is this the same as the tenderloin used for Beef Wellington?

Yes. A center-cut tenderloin roast is the classic cut for Beef Wellington. Trim it evenly and tie it so the shape stays uniform before wrapping.

Choice or Prime: which grade is this?

This roast is USDA Choice, the middle grade. Prime has more marbling, but tenderloin is lean in any grade, so the difference in tenderness is small.

Does it come trimmed and tied?

It is hand-trimmed, with the silver skin removed and the meat shaped for even cooking. Tying it with twine helps it hold a round shape while roasting.