An acronym for "Fuck I'm Good, Just Ask Me". Used by many Australians as a sign of triumph after completing a task, winning an award or just as a joke.
Also a song, "FIGJAM (Fuck I'm Good Just Ask Me)" by Butterfingers, an Australian band.
Bob: "Ahhh, finishedtiling that roof at last..."
Alan: "Yeah, FIGJAM!"