"Lak traders are purveyors of all kinds of boost chips, so naturally they're the ones you should talk to about getting more. Go up the stairs next to me, all the way to the upper terrace, and talk to Lak Trader Schrire. She'll tell you everything you need to know about collecting Lak and getting boost chips."
After accepting the quest, head up the stairs just north of Mentor Gildas. Lak Trader Schrire is at the top of the second flight of stairs.
"Hey, you're the one Uncle Gildas was talking about! He didn't tell you I was his favorite niece? How typical. Anyway, your Chaos Necklace is ready!"