The field of ale brewing (3)
I believe the answer is:
lea
'the field' is the definition.
(I've seen this before)
'ale brewing' is the wordplay.
'brewing' indicates anagramming the letters.
'ale' with letters rearranged gives 'LEA'.
'of' is the link.
(Other definitions for lea that I've seen before include "Open grassy land; river" , "Grazing land" , "pastoral setting" , "Open country" , "area of grassland" .)