Ruddy shower doing for vegetable (3,6)
I believe the answer is:
red pepper
'vegetable' is the definition.
(I've seen this before)
'ruddy shower' is the wordplay.
'ruddy' becomes 'red' (synonyms).
'shower' becomes 'pepper' (I've seen this before).
'red'+'pepper'='RED PEPPER'
'doing for' is the link.
(Other definitions for red pepper that I've seen before include "Salad vegetable" , "Variety of capsicum" , "Hot powdered condiment" , "Ripe fruit" , "pungent food" .)