PHIPPSBURG — When the cast and crew of “Message in a Bottle” sit down to eat lunch, they don’t moan about the bland contents of their brown bags.

Instead, the folks working on the Warner Bros. film in production in midcoast Maine enjoy such epicurean delights as chateaubriand, steamed sea bass, roast duck with orange sauce, and a full sushi bar.

The layout is provided by Chef Tony Kerum, who is one of the movie industry’s most in-demand caterers.

Clint Eastwood insists on him, as does “Message in a Bottle” star Kevin Costner.

“I wouldn’t settle for anything but the best,” said Kerum, whose Tony’s Food Service is based in Valencia, Calif. “If I wouldn’t eat it, I wouldn’t serve it. ”

Costner has used Kerum to cater the sets of “The Postman,” “The Bodyguard,” “Waterworld,” “Perfect World” and “Wyatt Earp.” Kerum also has served as caterer-to-the-stars for other big movies, among them “Forrest Gump,” “The Rock,” “Flashdance” and “On Golden Pond.

Since April, Kerum and his staff of five have been serving breakfast and lunch six days a week to about 200 people on the “Message In A Bottle” set. They work from a mobile kitchen, somehow preparing elaborate meals that by union rules have to be laid out every six hours.

After 20 years in the business, Kerum, 48, got a chance through his “Message in a Bottle” work to meet Paul Newman, who plays Costner’s father in the film.