Clue I do is incredibly tasty (9)
I believe the answer is:
delicious
'tasty' is the definition.
(I've seen this before)
'clue i do is incredibly' is the wordplay.
'incredibly' indicates an anagram.
'clue'+'i'+'do'+'is'='clueidois'
'clueidois' anagrammed gives 'DELICIOUS'.
(Other definitions for delicious that I've seen before include "Pleasant tasting" , "Scrumptious" , "Yummy" , "very nice" , "See 3" .)