Vegetable meal after unshelled crab (6)
I believe the answer is:
radish
'vegetable' is the definition.
(radish is a type of vegetable)
'meal after unshelled crab' is the wordplay.
'meal' becomes 'dish' (a dish is a particular meal).
'after' is a charade indicator (letters next to each other).
'unshelled crab' becomes 'ra' (I am not sure about this - if you are sure you should believe this answer much more).
'dish' put after 'ra' is 'RADISH'.
Can you help me to learn more?
(Other definitions for radish that I've seen before include "Root vegetable used in salads" , "Hard vegetable" , "3 down" , "Hottish salad plant" , "Bit of salad" .)