Slow-cookers brimming with chicken stew were turned on at 7 a.m. The first of 300 chicken legs went on the grill at 8. By that time, the barbecue had been smoking for 12 hours. The Thelathia Barnes Bailey Textbook Scholarship 2017 Soul Food Cook Off competition was off and running Tuesday before the food samplers’ taste buds had finished breakfast. Seven teams served bite-sized portions of their masterpieces to an overflow lunchtime crowd of hundreds in USC Lancaster’s Arnold Special Events Room.