After cooked beet, left with a nut (5)
I believe the answer is:
betel
'a nut' is the definition.
(I've seen this in another clue)
'after cooked beet left' is the wordplay.
'after' says to put letters next to each other.
'cooked' indicates an anagram (letters cooked into a new form).
'left' becomes 'L' (common abbreviation).
'beet' anagrammed gives 'bete'.
'bete' put next to 'l' is 'BETEL'.
'with' acts as a link.
(Other definitions for betel that I've seen before include "Asian palm and nut" , "stimulatingly chewed in Asia" , "leaves to chew" , "Plant leaf chewed in the East" , "Dried leaf of a plant chewed in Asia as a mild stimulant" .)