Writer left to tour huge wine region (5)
I believe the answer is:
mosel
'wine region' is the definition.
'mosel' can be an answer for 'wine' (I've seen this before). I'm not certain of the 'region' bit.
'writer left to tour huge' is the wordplay.
'writer' becomes 'me' (the person who wrote the clues).
'left' becomes 'l' (common abbreviation).
'to tour' is an insertion indicator (to tour can mean to go around).
'huge' becomes 'os' (abbreviation for outsize).
'me'+'l'='mel'
'mel' enclosing 'os' is 'MOSEL'.
Can you help me to learn more?
(Another definition for mosel that I've seen is " Wine".)