For Britain’s Marianne Jean-Baptiste, her 30-years-later reunion with the legendary filmmaker Mike Leigh as the star of “Hard Truths,” in theaters now, has been a remarkable triumph.

It was in Leigh’s 1996 “Secrets and Lies,” where she starred as a woman who discovers her birth mother is white, that Jean-Baptiste became the first Black British woman to be nominated for an Academy Award (as Best Supporting Actress).  For “Hard Truths” Jean-Baptiste has already won many year-end critics’ Best Actress awards, as well as a Critics Choice Awards Best Actress nomination. On Jan. 19 she finds out if she’s won a second Academy Award nomination, this time as Best Actress.

In “Hard Truths” Jean-Baptiste, 57, is magnetic as Pansy, a very troubled, consistently insulting, miserable wife and mother.  Pansy can’t help attacking anyone who is unlucky enough to come into her orbit – at the grocery checkout, a furniture store, even in a parking lot. Her invective cascades, like volcanic lava, meant to hurt.

Yet we see that when she wakes, it’s always with a terrified leap from her bed as if electrified and about to be attacked.

If she is one continuing torrent of total negativism, she can initially be amusing, generating in her over-the-top broadsides a comically unbalanced barrage of venom. Gradually, we see she’s mentally ill and not about to get treatment.

After that career breakthrough in “Secrets” Jean-Baptiste moved with her family to Los Angeles and worked continuously, in series like “Without a Trace” as an FBI agent or movies like the 2014 “Robocop” remake.

Leigh however has a unique method that begins with the cast investigating their character with improvisations that are recorded and eventually, in this case after 14 weeks, transformed into a shooting script. The actors, under Leigh’s direction, have really created their characters. Actual filming took another six weeks.

“Obviously, I’ve worked in a very traditional, conventional way on other things,” she said in a post-screening discussion with Leigh, “and just coming back to having the freedom to work in the way that Mike works, is just exhilarating.

“I mean, it’s terrifying as well. But you feel really free. And you trust him, because he trusts you ultimately.”

Besides being showered with awards, Jean-Baptiste has discovered that audiences really connect to Pansy, no matter how off-putting she may be.

“They’ve said, ‘You must have met my mother in law.’ ‘That’s my auntie.’ And you know what’s lovely? Some people have actually said, ‘I’m going to call my mum. Because I’ve just found her really difficult, and watching this has made me think, well, maybe she’s in pain or whatever.’

“It’s just giving people pause. You know, a bit more compassion and understanding.”

“Hard Truths” is in theaters