Craving to include dim assembly is a remarkable thing (9)
I believe the answer is:
humdinger
'remarkable thing' is the definition.
'humdinger' can be an answer for 'thing' (I have seen 'excellent thing' mean 'humdinger' so perhaps 'thing' could also mean 'humdinger'). I am not certain of the 'remarkable' bit.
'craving to include dim assembly' is the wordplay.
'craving' becomes 'hunger' (I've seen this in another clue).
'to include' means one lot of letters goes inside another.
'assembly' indicates anagramming the letters.
'dim' anagrammed gives 'mdi'.
'hunger' placed around 'mdi' is 'HUMDINGER'.
'is a' acts as a link.
Can you help me to learn more?
(Other definitions for humdinger that I've seen before include "Slang for remarkable person or thing - a real wow!" , "Excellent example" , "Fine example" , "Absolute belter" , "cracker" .)