There’s a new restaurant in town that is making a lot of buzz. McMahon’s Countryside Grille, 336 Old Colony Road, opened July 1, and already has regulars. “So far it has been everything we wanted it to be,” said owner Karyn McMahon. This business venture is a family affair, as Karyn’s husband, Chris, and their children, CJ, Nick, Karlene and Darcey, all have a role to play. Karyn is the face of the business who deals with the behind the scenes details. Chris and Nick can usually be found in the kitchen, cooking away. CJ is a waiter and designed the menu. Karlene and Darcey are learning the …