Bravo's "Top Chef"  Season 17 - All Stars LA features the fiercest group of competitors the show has seen with 15 finalists, front runners and fan favorites from seasons past who have all returned to finish what they started and battle it out for the coveted title.  Premiering with a supersized episode on Thursday, March 19 from 10 – 11:15 pm ET/PT, the Emmy and James Beard Award-winning series returns with host Padma Lakshmi, head judge Tom Colicchio and judge Gail Simmons.