As usual, regularly eating a second pastry (6)
I believe the answer is:
samosa
'pastry' is the definition.
(I've seen this before)
'as usual regularly eating a second' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'eating' indicates putting letters inside.
'second' becomes 'mo' (both are short periods of time).
'as'+'usual'='asusual'
The alternating letters of 'asusual' are 'ssa'.
'a'+'mo'='amo'
'ssa' placed around 'amo' is 'SAMOSA'.
(Other definitions for samosa that I've seen before include "Small Indian pastry of meat or vegetables" , "savoury pastry" , "tasty snack" , "Indian dish" , "Small Indian cake of meat or vegetables" .)