Cereal offered as true Scottish starters? (4)
I believe the answer is:
oats
'cereal' is the definition.
(type of cereal)
'offered as true scottish starters?' is the wordplay.
'starters?' indicates taking the first letters (I've seen 'starters' mean this).
The first letters of 'offered as true scottish' is 'OATS'.
(Other definitions for oats that I've seen before include "Cereal grass and seeds" , "Food for horses and Scots (said Dr Johnson)" , "Porridge ingredient" , "Food crop" , "Cereal plants" .)