It can obviously figure in a vegetarian repast (7)
I believe the answer is:
oatmeal
'it can obviously figure' is the definition.
The definition suggests a singular noun which matches the answer.
'vegetarian repast' is the wordplay.
'vegetarian' becomes 'oat' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'repast' becomes 'meal' (synonyms).
'oat'+'meal'='OATMEAL'
'in a' is the link.
Can you help me to learn more?
(Other definitions for oatmeal that I've seen before include "Eat loam (anag)" , "Porridge ingredient" , "It's boiled for porridge" , "Ground grain; colour" , "Basis of porridge" .)