The most common and most likely answer to this crossword clue is the 9 letter word ADVOCATED
I've seen this crossword clue in The Guardian
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Buddy explains!

The straight part
We know that "Recommended" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case recommended = advocated.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 ADVOCATED mean?
ADVOCATED verb- To plead in favour of; to defend by argument, before a tribunal or the public; to support, vindicate, or recommend publicly.
- To encourage support for something.
- (with for) To engage in advocacy.
- Having been argued in favor of.