Gent regularly tucking into prizewinning mushroom (10)

I believe the answer is:

champignon

'mushroom' is the definition.
(I've seen this before)

'gent regularly tucking into prizewinning' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'tucking into' indicates putting letters inside.
'prizewinning' becomes 'champion' (synonyms).
The alternating letters of 'gent' are 'gn'.
'gn' placed within 'champion' is 'CHAMPIGNON'.

(Another definition for champignon that I've seen is " mushroom".)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app