Painting technique in a spot restyled after one month (7)
I believe the answer is:
impasto
'painting technique' is the definition.
(I've seen this before)
'a spot restyled after one month' is the wordplay.
'restyled' indicates an anagram.
'after' means one lot of letters go next to another.
'one' becomes 'i' (Roman numeral).
'month' becomes 'm' (standard abbreviation).
'a'+'spot'='aspot'
'aspot' with letters rearranged gives 'pasto'.
'i'+'m'='im'
'pasto' put after 'im' is 'IMPASTO'.
'in' is the link.
(Other definitions for impasto that I've seen before include "Technique possibly Van Gogh's" , "Method of painting" , "artistic technique" , "Thick painting technique" , "Thick-paint technique" .)