The most common and most likely answer to this crossword clue is the 13 letter word CHATEAUBRIAND
I've seen this crossword clue in The Daily Telegraph
C
H
A
T
E
A
U
B
R
I
A
N
D
More clues leading to the result CHATEAUBRIAND
- French statesman talked heartlessly about a university man
- French writer's talk with journalist grabbing a university chap
- A hit with bean curd, a strange meat dish
- Wine maker’s marque includes one 27
- Romantic French writer ordering a Thai bean curd
- Diana, a butcher, chopped up piece of beef
- A butcher and I in mix-up about a steak
- Crab? Auntie had ordered steak
- Beneath French castle, munched rib and steak
Buddy explains!

The straight part
We know that "steak/steak" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case steak/steak = chateaubriand.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CHATEAUBRIAND mean?
CHATEAUBRIAND noun- A thick, juicy cut from the center of a beef tenderloin.