Same muscle (tenderloin); Chateaubriand is the thick centre section, filet mignon is the smaller tail-end medallion.
These are near equivalents in the way butchers and cooks use them. If you can source either one, you're very close to the same result.
The same muscle, cut two ways
Both come from the beef tenderloin, so they are equally tender. A chateaubriand is one thick piece from the centre of the tenderloin, cooked whole for two and sliced at the table. Filet mignon is the same muscle cut into individual steaks.
The difference is format, not quality. Choose a chateaubriand for a shared roast with a sauce, and filet mignon when everyone gets their own steak.
"Filet mignon" is not the same word everywhere
In the US, filet mignon means beef tenderloin steaks. In France, filet mignon on a menu or butcher's label usually means pork tenderloin. The French name for beef tenderloin steaks is tournedos. Chateaubriand keeps its name in every country in the catalog.
- UK
- Fillet steak.
- Spain
- Medallón de solomillo.
- Argentina
- Medallón de lomo.
- Italy
- Medaglione di filetto.
- France
- Tournedos.
How to cook each
Chateaubriand: sear it on all sides, then finish it in a moderate oven until the centre reaches medium-rare. Rest it for ten minutes and slice it thickly. Béarnaise is the classic sauce.
Filet mignon: steaks about 4–5 cm thick, seared hard on both sides and finished gently. The meat is lean, so it is less forgiving than a marbled steak past medium-rare. Butter basting or a pan sauce makes up for the missing fat.
Names by country
| Country | Chateaubriand | Filet mignon |
|---|---|---|
| 🇺🇸United States | Chateaubriand | Filet mignon |
| 🇬🇧United Kingdom | Chateaubriand | Fillet steak |
| 🇫🇷France | Chateaubriand | Tournedos |
| 🇪🇸Spain | Chateaubriand | Medallón de solomillo |
| 🇦🇷Argentina | Chateaubriand | Medallón de lomo |
| 🇲🇽Mexico | Chateaubriand | Filete medallón |
| 🇵🇹Portugal | Chateaubriand | Medalhão |
| 🇧🇷Brazil | Chateaubriand | Medalhão de filé |
| 🇮🇹Italy | Chateaubriand | Medaglione di filetto |
| 🇩🇪Germany | Chateaubriand | Filet Mignon |