Metes out the Dover sole, not over cooked (5)

'metes' is the definition.
(I've seen this in another clue)

'the dover sole not over cooked' is the wordplay.
'not' indicates named letters should be taken away.
'cooked' indicates an anagram (letters cooked into a new form).
'dover'+'sole'='doversole'
'doversole' with 'over' taken away is 'dsole'.
'dsole' anagrammed gives 'DOLES'.

'out' acts as a link.