HAY DAY: Mario Batali calls her “the new Zen mistress of simplicity in both technique and presentation.” Meet Australian kitchen sensation and New York Post columnist Donna Hay at the launch of her eighth book, “The Instant Cook” (HarperCollins, $34.95),Thursday from 5:30 to 7 p.m. at the Conran Shop, Bridgemarket (407 E. 59th St., at First Avenue). The book focuses on beautiful, simple and delicious dishes.

HOT ‘MAMA’: Just when Spanish cuisine couldn’t get hotter, along comes a book celebrating where it all began – in Spanish homes. In “La Cocina de Mama: The Great Home Cooking of Spain” (Broadway Books, $29.95), Iberian food expert Penelope Casas gathers some 175 recipes and personal memories from grannies and monks, not to mention the secrets of rabbit paella with artichokes and green beans from Josefa Acosta, the mama of the world’s most innovative chef, Ferran Adria.

KID AID: One in four New York kids doesn’t get enough to eat, a sorry fact that tomorrow’s Skip Lunch Fight Hunger campaign tries to change by asking workers to donate the amount they usually spend on lunch to the annual fund-raiser. Last year over 100 companies raised close to $100,000 in a single day. Find out more, and contribute on line at http://www.cityharvest.org/skiplunch