Extremely dry sandwiches are not pleasant to eat (6)
I believe the answer is:
dainty
'pleasant to eat' is the definition.
I can't tell whether this definition defines the answer.
'extremely dry sandwiches are not' is the wordplay.
'extremely' says to hollow out the word (remove centre letters) (letters on the extremes of the word are used).
'sandwiches' indicates putting letters inside (goes on either side like a sandwich).
'are not' becomes 'ain't' (non-standard version of 'isn't' or 'aren't').
'dry' with its middle removed is 'dy'.
'dy' going around 'aint' is 'DAINTY'.
Can you help me to learn more?
(Other definitions for dainty that I've seen before include "Petite and elegant" , "Choice" , "Exquisite" , "Small and beautiful" , "Delicately small and pretty" .)