The most common and most likely answer to this crossword clue is the 6 plus 4 letter word CORDON BLEU
I've seen this crossword clue in Financial Times
C
O
R
D
O
N
B
L
E
U
More clues leading to the result CORDON BLEU
- Gracious fellow beginning to buy foreign bread of a very high culinary standard
- Wow academic bishop with currency of very high distinction
- Jeremy’s left wing academic, lube applied, gets prestigious award
- My double “n” is wrong, according to top-class cook
- Cloud borne away in first-class style
- Chef’s unusual blunder – cook finally ousted
- Bend 9 round high-class cookery
- Of a very high standard, ‘boron’ clued cryptically
- Chef’s unusual blunder — cook ultimately dismissed
- High standard way to cook red bun. Cool!
Buddy explains!

The straight part
We know that "Chef" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case chef = cordon bleu.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 CORDON BLEU mean?
CORDON BLEU noun- One of two species of passerine birds in the genus Uraeginthus.