How to make Elba popular (11)
I believe the answer is:
fashionable
'popular' is the definition.
(similar in meaning)
'how to make elba' is the wordplay.
I cannot quite understand how this works, but
'make' could be 'fashion' (both can mean manufacture) and 'fashion' is found within the answer.
an anagram of 'elba' is 'able' which is within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for fashionable that I've seen before include "Modish" , "Trendy" , "What's in" , "A la mode" .)