To a friend, Sarah's very tasty! (6)
I believe the answer is:
salami
'to a' is the definition.
I can't tell whether this definition defines the answer.
'friend sarah's very tasty' is the wordplay.
I cannot really understand how this works, but
'friend' could be 'ami' ('friend' in French) and 'ami' is located in the answer.
'sarah' could be 'sal' (Sally is a common pet form of Sarah) and 'sal' is found within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for salami that I've seen before include "Hooked" , "Cured meat" , "Spicy preserved sausage" , "One kind of tactics" , "Italian sausage (a kind of tactics?)" .)