Start seeing reforms close to Brussels (7)
I believe the answer is:
genesis
'start' is the definition.
(I've seen this before)
'seeing reforms close to brussels' is the wordplay.
'reforms' indicates an anagram.
'close to' suggests the final letters (the 'close' to the word).
The final letter of 'brussels' is 's'.
'seeing' is an anagram of 'genesi'.
'genesi'+'s'='GENESIS'
(Other definitions for genesis that I've seen before include "rock group" , "Origin -- see sign (anag)" , "First book of the Old Testament" , "religious book?" , "name of group" .)