Cooking fish in prison — one with new governor at its head (4-6)

I believe the answer is:

stir-frying

'cooking' is the definition.

'fish in prison one with new governor at its head' is the wordplay.
'fish in prison' becomes 'stirfry' (I can't explain this - if you can you should believe this answer much more).
'one with' becomes 'i' (I've seen this in other clues).
'at its head' indicates taking the first letters.
The initial letters of 'new governor' is 'ng'.
'stirfry'+'i'+'ng'='STIR-FRYING'

I've seen this clue in The Guardian.

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