Cooked slab in the morning, in charge of vinegar (8)
I believe the answer is:
balsamic
'vinegar' is the definition.
(I've seen this before)
'cooked slab in the morning in charge' is the wordplay.
'cooked' is an anagram indicator (letters cooked into a new form).
'in the morning' becomes 'am' (AM on a clock).
'in charge' becomes 'ic' (abbreviation for 'in charge').
'slab' with letters rearranged gives 'bals'.
'bals'+'am'+'ic'='BALSAMIC'
'of' is the link.
(Other definitions for balsamic that I've seen before include "BAs claim this strange type of vinegar" , "smelling of perfume" , "Variety of vinegar" , "Concerned with healing" , "Italian type of vinegar" .)