"Envy" sets out to test the comedic limits of flan. But just how funny is custard baked with a caramel glaze?

The characters in this movie about backstabbing and friendship repeat the word "flan" endlessly — the equivalent of watching two 6-year-old's giggle themselves into a fit over some inexplicable joke. Sure, they're having a good time — but what about the onlookers, in this case the audience?

Anyone buying a ticket to this debacle may find themselves turning to some other unlucky soul in the theater and asking: "Are they really making joke after joke after joke about flan?"

Sitting down to watch "Envy" is like sitting down for a meal made of gourmet ingredients that was cooked into flavorless mush.

It has a strong cast — starring Ben Stiller and Jack Black — a fine director, "Rain Man" Oscar winner Barry Levinson, and a producing credit from "Curb Your Enthusiasm" and "Seinfeld" co-creator Larry David, who reportedly worked on the script but had his name removed.

Somewhere along the way, these talented individuals failed to connect. "Envy" crawls to its finish through a minefield of poor taste and comedic misfires.

Black plays Nick Vanderpark, an inventor who creates an aerosol spray that makes dog feces disappear. It's called "Va-POO-rize." He becomes a multi-jillionaire and Stiller, as his pal Tim Dingman, is angry and vengeful over his buddy's success.

Then, he inadvertently kills Black's prized horse and buries it in his yard. He feels horribly guilty over this, and the rest of the movie follows him trying to cover his tracks.

Whatever influence David had over the story (the screenplay is credited solely to Steve Adams) his trademark brand of bitter humor may work better when confined to a half-hour.

And what has become of Levinson?

He has made some great dramas that have true comedy in them ("Good Morning, Vietnam," "Diner" and "Avalon"). But his comedies ("Wag the Dog" is the lone exception) are usually painful flops: "Jimmy Hollywood," "Toys" and "An Everlasting Piece."

"Envy" is rated PG-13 for occasional use of strong profanity (including one usage of the so-called R-rated curse word), crude sight gags about and references to bodily functions, and a brief act of violence (animal cruelty). Running time: 99 minutes.