The most common and most likely answer to this crossword clue is the 9 letter word UNDERDONE
I've seen this crossword clue in The Guardian
U
N
D
E
R
D
O
N
E
Buddy explains!
The straight part
We know that "Such a steak is rarely served" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case such a steak is rarely served = underdone.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 UNDERDONE mean?
UNDERDONE adjective- Insufficiently cooked; undercooked