Elaia Estiatorio, a Greek restaurant in Bridgehampton, will offer a three-course prix fixe menu for $32 per person on Sundays, Tuesdays, Wednesdays, and Thursdays. Fred Bollaci, the author of the “The Restaurant Diet: How to Eat Out Every Night and Still Lose Weight,” will be at BookHampton in East Hampton on Saturday at 4 p.m.