It may be served on board after that at regular times (4)
I believe the answer is:
feta
'it may be served on board' is the definition.
(as in a cheese board)
'after that at regular times' is the wordplay.
'at regular times' indicates alternate letters.
'after'+'that'='afterthat'
The alternating letters of 'afterthat' are 'FETA'.
(Other definitions for feta that I've seen before include "A ewe's, goat's milk cheese" , "Greek dairy product" , "Goat's or sheep's milk cheese" , "White and salty goat or sheep cheese" , "food there" .)