Calmed down and when the food came in followed suit (8)
I believe the answer is:
appeased
'calmed down' is the definition.
(appeasing is a kind of calming down)
'came in followed suit' is the wordplay.
'came' becomes 'peas' (I am not sure about this - if you are sure you should believe this answer much more).
'in' indicates putting letters inside.
'followed suit' becomes 'aped' (I've seen this in another clue).
'peas' placed within 'aped' is 'APPEASED'.
'and when the food' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for appeased that I've seen before include "Placated, pacified" , "Calmed" , "Conciliated" , "Changed a deep sap and mollified" , "Assuaged, mollified" .)