Large tuna? Managed to form into little pieces? (9)
I believe the answer is:
granulate
'form into little pieces?' is the definition.
I can't judge whether this defines the answer.
'large tuna? managed' is the wordplay.
'managed' indicates an anagram.
'large'+'tuna'='largetuna'
'largetuna' with letters rearranged gives 'GRANULATE'.
'to' is the link.
Can you help me to learn more?
(Other definitions for granulate that I've seen before include "Break into fine particles" , "Break down into small fragments" .)