Midnight! Boss gets soup (5)
I believe the answer is:
gumbo
'soup' is the definition.
(type of Cajun soup)
'midnight boss' is the wordplay.
'midnight' becomes 'g' (the middle letter in 'night').
'boss' becomes 'umbo' (the boss on a shield).
'g'+'umbo'='GUMBO'
'gets' is the link.
(Other definitions for gumbo that I've seen before include "Patois" , "Spicy Cajun soup" , "Cajun chicken dish" , "Thick soup" , "Okra pods" .)