That's a Leek Moth, Acrolepiopsis assectella. This species is spreading west in the county after being recorded for the first time in 2007 (in Cardiff). Yours might be the most westerly to date - there were a couple of records from Cowbridge last year.
Oh that's great. Ta v much. I did consider it and noted it as a pest but did not think it was the right region for one!