Brown bread perfectly absorbs soup at first (5)
I believe the answer is:
toast
'brown bread' is the definition.
(I've seen this before)
'perfectly absorbs soup at first' is the wordplay.
'perfectly' becomes 'to a t' ('to a T' or 'to a tee' can mean perfectly).
'absorbs' means one lot of letters goes inside another.
'at first' suggests taking the first letters.
The first letter of 'soup' is 's'.
'toat' going around 's' is 'TOAST'.
(Other definitions for toast that I've seen before include "Raise a glass to (someone)" , "person much admired" , "Perhaps all the best" , "Grill - clinking of glasses" , "Formally drink a health" .)