One's beginning to paint, respecting such a technique (7)
I believe the answer is:
impasto
'a technique' is the definition.
(painting technique)
'one's beginning to paint respecting' is the wordplay.
'one's' becomes 'I'm' ('one is' is a formal way of saying 'I am').
'beginning to' indicates taking the first letters.
'respecting' becomes 'as to' (both can mean 'relating to').
The initial letter of 'paint' is 'p'.
'im'+'p'+'asto'='IMPASTO'
'such' acts as a link.
(Other definitions for impasto that I've seen before include "artist's application" , "Technique using thick paint" , "Thick coat required" , "Art technique of laying paint on thickly" , "Painting with pigment laid on thick" .)