Rare place for artist Ken's staff (9)

I believe the answer is:

underdone

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'rare' is the definition.
(synonyms)

I don't understand the rest of the clue.

(Other definitions for underdone that I've seen before include "Not fully cooked, more time needed" , "could be rare" , "Inadequately cooked" , "Not sufficiently cooked" , "raw!" .)

I've seen this clue in the Sydney Morning Herald.

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