‘Chicago Fire’ star to appear at Chicago’s iO improv mecca

Christian Stolte, who stars as Mouch on “Chicago Fire,” will showcase his comedic chops (which he often does exhibit on the hit NBC drama) as the guest monologist at “The Armando Diaz Theatrical Experience and Hootenanny” at iO Theatre on Monday. “Armando” is the longest-running show in Chicago, having been launched in 1995, featuring special guests weekly. … Also at iO, owner and improv queen Charna Halpern just got a call from former “Saturday Night Live” ensemble member Paul Brittain — happy to learn he will be bringing back “Topaz” to iO at 10:30 p.m. Saturday. “Topaz” was a show Brittain created at iO before he left to join SNL in 2010, for what turned out to be a relatively short run ending in January 2012.