Sound off, right away, after one tucked into crusty roll (9)
I believe the answer is:
croissant
'sound off right away' is the definition.
I can't tell whether this definition defines the answer.
'one tucked into crusty roll' is the wordplay.
'one' becomes 'i' (Roman numeral).
'tucked into' means one lot of letters goes inside another.
'crusty' becomes 'cross' (both can mean bad-tempered).
'roll' becomes 'ant' (I can't justify this - if you can you should give a lot more credence to this answer).
'i' put within 'cross' is 'croiss'.
'croiss'+'ant'='CROISSANT'
'after' is the link.
Can you help me to learn more?
(Other definitions for croissant that I've seen before include "A rich crescrent-shaped bread roll" , "Continental breakfast crescent" , "Breakfast roll" , "food item" , "that baker turns out" .)