Shelter knight from vegetable (4)

I believe the answer is:
leek
Here is my best explanation:
'vegetable' is the definition.
(leek is a kind of vegetable)
'shelter knight' is the wordplay.
'shelter' becomes 'lee' (I've seen this before).
'knight' becomes 'k'.
'lee'+'k'='LEEK'
'from' is the link.
This clue was last seen in Mirror