Everything in the pot can be eaten by a vegetarian (7)
I believe the answer is:
shallot
'be eaten by a vegetarian' is the definition.
I can't judge whether this defines the answer.
'everything in the pot' is the wordplay.
'everything' becomes 'all' (all things).
'in the' means one lot of letters goes inside another.
'pot' becomes 'shot' (I can't justify this - if you can you should give a lot more credence to this answer).
'all' inserted into 'shot' is 'SHALLOT'.
'can' is the link.
Can you help me to learn more?
(Other definitions for shallot that I've seen before include "Type of 12" , "Scallion" , "One may get into a stew" , "Onion-like plant with clusters of bulbs" , "Edible onion-like bulb" .)