Finding exactly the right recipe for a quirky, sweet-natured comedy is deceptively difficult. Add a little too much eccentric behavior and the characters won't have a well-rounded flavor. Lean too heavily on sentimentality and audiences will gag on the syrupy sweetness. Fortunately, writer-director Adrienne Shelly concocted a winning combination with "Waitress."

Keri Russell (shining even brighter than she did on TV's "Felicity") stars as Jenna, a small town woman stuck in a dead-end marriage to self-centered Earl (Jeremy Sisto, "Six Feet Under"). Her only release comes from baking pies until she discovers she's pregnant and meets considerate (and handsome) ob-gyn Dr. Pomatter (Nathan Fillion, "Serenity").

The story develops in not-entirely-predictable ways as Jenna struggles with major life decisions that inspire dishes like "Baby Screaming It's Head Off in the Middle of the Night and Ruining My Life Pie" and "Earl Murders Me Because I'm Having an Affair Pie."

Russell and Fillion are both naturally likable performers well chosen for roles that capitalize on their comedic gifts. They're surrounded by a strong supporting cast, including the fearless Sisto (he's building an admirable career on edgy, unglamorous characters), sassy Cheryl Hines ("Curb Your Enthusiasm"), old pro Andy Griffith and the filmmaker herself.

It should be acknowledged that "Waitress" arrives with some dark off-screen baggage. Shelly was killed last year, months prior to the film's premiere at Sundance. Although she had directed before, Shelly's assured work here suggests she was about to begin a new, higher-profile chapter in her career.

The tragedy represents a stark paradox to the film's overriding positivity, but nothing can distract from the inherent joy of experiencing this undeniably tasty creation.