Cajun Aces Married chefs Sam and Cody Carroll develop and introduce new dishes at their restaurant in the two-episode premiere of this unscripted series. 8 and 8:30 p.m. Food Network
Saturday Night Live Saoirse Ronan (“Lady Bird”) hosts, and U2 is the musical guest. 8:29 and 11:29 p.m. NBC
Dirk Gently's Holistic Detective Agency As their enemies converge from all sides, Dirk (Samuel Barnett) has to shake off his insecurity and take charge to save bickering Todd and Amanda (Elijah Wood, Hannah Marks) from certain death. Christopher Russell, Fiona Dourif, Alan Tudyk and Dustin Milligan also star. 9 p.m. BBC...