Capital worker, one tucking into starchy pudding (8)
I believe the answer is:
santiago
'capital' is the definition.
(capital of Chile)
'worker one tucking into starchy pudding' is the wordplay.
'worker' becomes 'ant' (worker is a type of ant).
'one' becomes 'i' (Roman numeral).
'tucking into' is an insertion indicator.
'starchy pudding' becomes 'sago' (type of pudding).
'ant'+'i'='anti'
'anti' inserted inside 'sago' is 'SANTIAGO'.
(Other definitions for santiago that I've seen before include "City" , "Capital of Chile" , "Chile's capital" , "Chilean capital" , "South American capital" .)