The dark Swiss chocolate analogy fits the Swiss comedy “My Wonderful Wanda” to a T, a bitter, wincing farce with an aftertaste that leaves you with a smile.

Death and new life, cultural prejudices and that Swiss obsession with money play into a film that is Germanic in its darkness, as subtle as a wet slap and funny? Eventually.

Wanda, played by Agnieszka Grochowska, is a Polish 30something, a single mother of two who travels by bus to her three month-long shifts with the German Swiss Wegmeister-Gloor clan. They’re rich, living in a lakeside manse. But the patriarch of their engineering firm, Josef (André Jung) had a stroke and is confined to his bed. Wanda is his favorite in-home caregiver.

His imperious wife Else (the great Marthe Keller) may feign warmth, now and again, to this woman who “works for us.” But she isn’t shy about brusquely setting boundaries.

When she asks Wanda to take on housekeeping duties, two things emerge. First, this family is a bit of a nightmare. Wanda simply won’t take her first offer for the added workload. And second, the fact that Wanda’s Polish speaks volumes. These rich cheapskates hired a bargain. they’re sure they can push around.

Son Gregor (Jacob Matschenz) still lives at home with his parents, the engineer-heir to the family firm but very slow to graduate from college. His real passion is birding, and he serenades Wanda — whom he’s sweet on — with a mockingbird’s repertoire of bird calls.

But Josef’s attachment is deeper. He, after all, has the money. And he’s not shy about bellowing “WANDA” in the middle of the night, summoning her for a “happy ending,” which supplements her income.

Josef tends to pout when she’s not at his beck and call. And when his daughter, Sophie (Birgit Minichmayr) barges in for his 70th birthday party and insists on assigning him therapy and pushing “my wonderful Wanda” into the background, things turn testy.

That’s when we pick up on how awful the Wegmeister-Gloors can be. Their offenses range from selfishness and rudeness to open hostility, their acting-out begins with insults and crescendos with screaming tantrums.

Wanda, who needs the cash, just has to take it.

And then a complication enters the picture, one that involves a Frühschwangerschaftstest — German for “peeing on a stick — and changes the dynamic in a big way.

Director and co-writer Bettina Oberli is slow to give away the tone she’s shooting for here. Some scenes make you cringe and the upper class cruelty can make you wince.

The matriarch laments old age, how “friends disappear, and with them, their occasions” (in German and Polish with English subtitles). But Josef fields birthday cards with gruff bemusement. “They’re still alive?”

We know it’s a comedy because a cow becomes a plot point, covering up shenanigans and revealing deep cultural prejudices.

And then daughter Sophie arrives — callous, mistrusting and spiteful — and we have a villain we can sink our teeth into. The Austrian Minichmayr (“Downfall,””The White Ribbon,” “Perfume”) puts on an audition for Nazi concentration camp guard roles with her bravura bullying and repertoire of petty humiliations.

She is so over-the-top you keep waiting for somebody — preferably a woman — to slap her. And when it happens, you eagerly hope it happens again.

Grochowska, of the recent singing competition drama “Teen Spirit,” gives away Wanda’s powerlessness in just her eyes. She has to sneak off to Facetime her children back in Poland. And whatever Josef’s affection for her or Gregor’s attentions might bode, it is women who either tolerate her or instinctively mistrust her who hold her fate.

Grochowaska’s turn strikes an awkward balance between how much Wanda can endure, and making us guess what upside she sees in all of this.

Like us, her Wanda is taking a tiny bite of this bitter chocolate with a grimace, hoping that something sweet kicks in eventually.

MPA Rating: unrated, sex, profanity

Cast: Agnieszka Grochowska, André Jung, Birgit Minichmayr, Jacob Matschenz and Marthe Keller

Credits: Directed by Bettina Oberli, script by Bettina Oberli, Cooky Ziesche. A Zeitgeist release.

Running time: 1:51