[4] Co-written by Ephron and her sister Delia, the film features an ensemble cast which includes Steve Martin, Madeline Kahn, Rita Wilson, Anthony LaPaglia, Garry Shandling, Rob Reiner, Juliette Lewis, Adam Sandler,[3] and Liev Schreiber in his film debut.

In Venice, Los Angeles on Christmas Eve, an ex-con named Felix is being chased down the road by his angry, pregnant girlfriend, Gracie.

Philip receives an eviction notice from the landlord, Stanley, who is planning to convert the building to condominiums.

The hotline is not too busy on Christmas eve, but they do get a call from a woman who is afraid of the "Seaside Strangler" (a serial killer who has recently targeted women in the neighborhood), and a call from Chris, a depressed transvestite who wants to visit the office in person so as to get away from his judgmental family.

Chris arrives at the office; Gracie opens the door for her so quickly that she accidentally strikes Mrs. Munchnik and knocks her unconscious.

Mrs. Munchnik awakens, witnesses their dancing, and threatens to sue Philip for withholding information of the eviction and for inappropriate office behavior.

Meanwhile, Philip throws the fruitcake out of the office window and accidentally smashes the windshield of Mrs. Munchnik's car, just as she is about to drive away.

An hour later, Felix (having regained consciousness and escaped from the hospital) arrives at the office brandishing a gun.

Not wanting Gracie to go to jail, Felix grabs the gun, runs to the roof of a building, and threatens to commit suicide.

They find fishing line and kelp, the Seaside Strangler's weapons of choice, revealing Stanley to be the serial killer.

The website's critical consensus reads: "Mixed Nuts may provoke strong allergic reactions in all but the most undemanding filmgoers - and the most forgiving Steve Martin fans.”[7] On Metacritic, the film had a weighted average score of 14 out of 100 based on 16 critics, indicating "overwhelming dislike.”[8] Audiences surveyed by CinemaScore gave the film a grade "C+" on scale of A to F.[9] Janet Maslin's review in The New York Times mentioned a corpse depicted in the story and wrote that the film "is about as funny as that corpse and about as natural"[10] Variety staff wrote that "director/co-scripter Nora Ephron pitches the humor at a cacophonous level and displays the comedic equivalent of two left feet in evolving an absurdist, slapstick yarn.

Truly alarming is watching some fine performers, including Kahn and LaPaglia, at their very worst.”[11] Roger Ebert of the Chicago Sun-Times wrote: "The movie has a first-rate cast and crew; it's Nora Ephron's first directing job since the wonderful Sleepless in Seattle [...] Maybe there's too much talent.