Starter of bran flakes a caterer put out in a dish first thing? (9,6)
I believe the answer is:
breakfast cereal
'a dish first thing?' is the definition.
(I've seen this before)
'starter of bran flakes a caterer put out' is the wordplay.
'starter of' suggests taking the first letters.
'put out' indicates anagramming the letters.
The first letter of 'bran' is 'b'.
'flakes'+'a'+'caterer'='flakesacaterer'
'flakesacaterer' is an anagram of 'reakfastcereal'.
'b'+'reakfastcereal'='BREAKFAST CEREAL'
'in' is the link.
(Another definition for breakfast cereal that I've seen is " dish first thing?".)