Rioja isn't regularly seen in this joint (5)
I believe the answer is:
roast
'this joint' is the definition.
('roast' can be a synonym of 'joint')
'rioja isn't regularly seen' is the wordplay.
'regularly seen' means one should take alternating letters.
'rioja'+'isnt'='riojaisnt'
The alternating letters of 'riojaisnt' are 'ROAST'.
'in' acts as a link.
(Other definitions for roast that I've seen before include "Criticise severely" , "Heat strongly - criticise excessively" , "The Sunday -----, with all the trimmings!" , "Have a go at" , "dish of lamb, say" .)