The most common and most likely answer to this crossword clue is the 9 letter word PREPARING
I've seen this crossword clue in Financial Times
P
R
E
P
A
R
I
N
G
Buddy explains!

The straight part
We know that "Dressing/cooking" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dressing/cooking = preparing.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 PREPARING mean?
PREPARING verb- To make ready for a specific future purpose; to set up; to assemble or equip.
- To make ready for eating or drinking; to cook.
- To make oneself ready; to get ready, make preparation.
- To produce or make by combining elements; to synthesize, compound.
- Preparation