Anonplz---I don't know were chamin de vert is???But I do know you can get cassoulet(I belive it is produced by Rougie)in jars at Hamel in the Jean Talon Market,and also at a little store on the opposite side of the market(near Bruilerie St.Dennis)in a market which sells only Quebecois product.
When I ran a fancy food store we would get cassoulet,gras d'oie,soupe de poisson ect,,,under the Petrossian lable(yes the caviar folks)so if you are in NYC stop by Petrossian,treat yourself to a nice lunch,and shop in their retail shop next door.
A company called D'Artanagne sells all sorts of Gascogne goodies.They are based in new york but are widely marketed and also do mail order.