Julianne Moore has had an extraordinarily wide-ranging acting career. In the 40 years that she’s lit up the stage and the small and silver screens, she’s starred in independent films and blockbusters, action movies and rom-coms, soap operas and searing dramas, and that most divine of comedies, The Big Lebowski. Along the way, she has won sacks of awards, including a Bafta, several Golden Globes, a clutch of Emmys and a Best Actress Oscar for playing an Alzheimer’s sufferer in Still Alice (which she reportedly keeps hidden at the back of a bookcase).

So is there anything else she’d like to achieve professionally? "It occurs to me that I’ve never played any kind of monster or creature, and I’m curious about that," she says. "What’s that like? How do you devise that identity? How do you know who they are? Do you make them human? Do you make them 'other'?"

Tweed dress, Chanel

Some might feel that in her latest film, the psychodrama May December, she has done just that. Moore plays Gracie, an apparently conventional and happily married mother who, it is revealed, spent time in prison after having an affair with a 13-year-old, Joe. Two decades later, the couple remain together, bringing up their family, but their fragile equilibrium is disrupted by the arrival of Elizabeth (Natalie Portman), an actress researching Gracie for a biopic.

"I started digging around with the part, trying to figure it out, but I was like, oh my God, this is so hard! Gracie is a person who’s really tortured. It’s dark stuff," Moore admits. "What was interesting to me was the distance between the narrative she projects, of this great love story and the choice she was compelled to make out of love, and what actually happened. The transgression is so vast that there’s a tremendous amount of tension and emotional volatility underneath."

Gabardine jacket; matching trousers; gold and silver earrings, all from a selection, Bottega Veneta

Indeed, the unsettling black humour of the film lies in Gracie’s unceasing efforts to portray her life and marriage as a Mills & Boon fantasy, via her job as a home baker and a wardrobe that majors on the pink and frilly, while being unable to conceal the hysteria that’s just below the surface. "When you see Gracie lose it, that unbridled emotion is where she is all the time. Even in the scenes where she appears to be placid, there’s that underneath it, always," says Moore.

Her nuanced, disconcerting performance makes it hard to write Gracie off simply as an evil paedophile; indeed, leaving the screening, I was surprised to find myself just as revolted by Elizabeth, who turns out to be as predatory and manipulative as her subject.

Jersey T-shirt, jeans, leather boots, from a selection, all Celine by Hedi Slimane. Rose gold and diamond earrings, gold bracelet, both Cartier

For Moore, the real villain of the piece is American tabloid culture. "When we sensationalise these stories, we dehumanise them. I was really upset by this when Nicole Brown Simpson was murdered, and she was on the cover of all of these magazines, so that you somehow felt she was still alive. I do think that there’s something interesting in examining our behaviour around the consumption of these stories."

Linen jacket, matching trousers, leather boots, all the Row. Rose and white gold and diamond earrings, gold and diamond ring, gold ring, all from a selection, Tiffany & Co

I suspect there are not many actors of Moore’s stature who would take the risk of portraying an abuser with such understanding, but she revels in bringing humanity to complex female roles, as seen in Still Alice and A Single Man. Besides which, May December gave her the opportunity to work for the fifth time with the director Todd Haynes, for whom she has become a muse.

Their partnerships have always been fruitful and fascinating. Haynes gave Moore her first lead role in Safe (1995), as a suburban housewife who develops numerous chemical sensitivities and has to abandon her cosseted consumerist LA lifestyle; while the part he wrote for her in Far From Heaven (2002), a drama set in 1950s America about a woman who falls in love with her Black gardener after she discovers that her husband is gay, won her numerous accolades. “I love Todd,” she says. “It’s been a great honour of my life to be his collaborator. I don’t think I would have been able to do [May December] without somebody I trusted, and who gave me so much support and context, and framing and intelligence behind everything. But because it was him, and because of Natalie, and Charles [Melton, who plays Joe] too, we actually had an amazing time.”

Jersey T-shirt, jeans, both Celine by Hedi Slimane. Rose gold and diamond earrings, gold bracelet, both Cartier

"I’ve never played any kind of monster and I’m curious about that. Do you make them human? Do you make them 'other'?"

Today, she's dressed down in an open-necked white shirt and jeans, with a bronze St Christopher’s medal around her neck made by her friend, the jewellery designer Lisa Eisner, to protect her on her travels. That trademark red hair is scraped into a knot on the top of her head; she has thick-rimmed glasses on her nose and apparently no make-up on her porcelain skin. Nevertheless, she somehow manages to look mesmerisingly beautiful and elegant, even over Zoom. It’s no surprise to learn that Bottega Veneta has just signed her up as an ambassador. "I’ve known Matthieu [Blazy, the designer] since he was an assistant at Calvin Klein," she says. "He’s a tremendous talent." She sat on the front row at his Milan show last season, eliciting much neck-craning. "I think fashion people are so creative, and I love their curiosity for culture and art. Anything that lends itself to expression of humanity is interesting to me."

Her day-to-day wardrobe is, she says, "pretty normal. I have to wear sneakers or boots, because I’m on the subway all the time, and I like a great coat, and a great jacket, and I’m very invested in my jeans and pants... I have a city wardrobe that’s very, very functional. The goal, too, is to find something that aligns with who I am, especially with red-carpet dressing, though it might feel like an exaggerated version of my personality or interests. Years ago, when I wore things, it was much more willy-nilly. It was like – oh, that’s a pretty dress. But now I’ll be much more conscious if it doesn’t feel like me."

Wool twill shirt; matching cape; matching trousers; ceramic and silver earrings, all from a selection, Bottega Veneta

Moore is talking to me from her New York home, where she’s trying to get over a nasty cold before embarking on a whirlwind publicity tour for May December, shuttling between LA and New York before flying to London – "it’s a tsunami of activity!" But it’s one she’s glad to undertake, since the carefully orchestrated press campaign for the movie’s release had to be initially abandoned because of the SAG-AFTRA actors’ strike, which also halted filming on Moore’s next film, a thriller titled Echo Valley.

"Todd was out there all by himself you know, doing the festivals, and we kept thinking that the strike would resolve, and they would set up these press dates, and then they would cancel them. So, I think we’re all really, really relieved to be going out there with him." (I’d envisaged her having a blissfully relaxing summer at her house in the Hamptons, but she says "it was less unstructured than I thought it would be", involving working with a pressure group on gun safety, getting her daughter set up at Northwestern University and visiting her father. "Actually, there’s a lot going on!")

Gabardine jacket; matching trousers; gold and silver earrings, all from a selection, Bottega Veneta

Moore’s other upcoming project, Mary & George, is very different – a period romp coming soon to Sky Atlantic and Now, based loosely on the historical figure of Mary Villiers, who propelled her son George to the Jacobean Royal court, where he was soon a favourite – and possibly a lover – of King James I, and rose to become the Duke of Buckingham. Moore spent several months at the start of last year living in London and driving to film scenes at various stately homes. She found it "incredibly daunting, because I was the only American person in an entirely British cast. So I was, like, what am I doing here? But it was a lot of fun. It was kind of a crazy role, and very different from anything I’d done before. London is a beautiful city, with wonderful people, and I worked with so many tremendously talented actors. Nicola Walker, man! I developed such a crush on her. I was always so excited when she was there."

Nappa leather dress; matching skirt, both from a selection, Bottega Veneta

Moore has a UK passport because her mother Anne was Scottish and emigrated to America as a child. "Something has always stayed with me," she says. "I actually wrote a kids’ book about being a first-generation American." There’s certainly an observant, outsiderish quality to her, which must be a great asset to her as an actress. It seems to stem from the way she was brought up – that, and inheriting her mother’s Celtic colouring. "I was always really little, skinny, redheaded and freckly, so I didn’t play outdoors as much as other kids did," she explains. "And we moved around constantly, because my dad was in the Army. I wasn’t sporty at all, I never made the cheerleading team, or anything like that. So I just started trying out for school plays with all the other misfits and I would always get the lead in something. It didn’t seem hard – I felt like I could hear the voice in my head, but I don’t think I knew that was unusual."

When her father was posted to Germany, her drama teacher there told her that she could turn professional, and gave her lists of drama colleges. "I went home and said to my parents: 'I’m going to be an actor!' And they were like: 'No, come on!' I’d never been to a real play. I’d only seen community theatre and high-school theatre, but I went to the movies and I watched television a lot."

Gabardine shirt, matching trousers, leather heels, all Saint Laurent by Anthony Vaccarello. Rose gold and diamond earrings, Cartier

Her parents, though disappointed their daughter had no interest in a secure professional career, were willing to support her dream. "My mother came with me to the United States to audition for schools, and I remember at one audition, I was the only person with my mother there, so she said, 'I’m going to go for a walk and come back for you later' – she didn’t want to embarrass me."

Moore won a place at Boston University to study theatre, and two years after graduating, had joined the cast of the long-running TV soap As the World Turns, playing two half-sisters, and, three years in, winning her first Emmy.

"I never made the cheerleading team. I just started trying out for school plays with all the other misfits"

She met her husband, the director Bart Freundlich, in 1996 on the set of The Myth of Fingerprints, which he wrote and directed, and they have two children, Caleb, who is 26, and Liv, 21. "I feel grateful I have a relationship that’s as rewarding as it is, because it’s something I really wanted to have," she says. What’s the secret of her happy marriage? She ponders. "One thing is not to spend too much time apart," she says. "You cannot be intimately involved in somebody else’s life if you are not there. The same way that you can’t parent someone if you’re not there: you know you have to be present. We love to be at home. We love family time with our kids, with each other and our dog, and we love to watch movies together and cook and eat together."

Nappa leather dress, leather mules, gold and silver earrings, all from a selection, Bottega Veneta

For a long time, Moore accepted roles only if they could fit around family life. "I didn’t travel outside New York because I needed to be there while they were in school. So if I did a little movie, it had to be shot in the city, and if it was a bigger thing, we’d have to move it to summertime so we could all go. Being able to make those decisions and have that kind of flexibility in my life has been amazing."

Now that both of her children have left home, she is free to travel for work, but when I ask if she’s relishing her lack of responsibility, she admits she found herself unexpectedly lonely while filming Mary & George. "It was the first time I’d said, I don’t have kids at home. I can actually go away and be on location somewhere. And it was way harder than I anticipated. So that was an interesting lesson. I don’t want to be away for months at a time without my husband. I want a community, I want to be with my family, I want to see my girlfriends – and I want to do nuanced, interesting, compelling work and be able to support myself. Life is really short, and I don’t want to throw it away on one thing, you know? I really do want to have all of it."

Though to be honest, it’s hard to think of anything Julianne Moore might have missed out on in the course of that extraordinary career – apart, of course, from playing Godzilla...

‘May December’ is available to watch on Sky Cinema. ‘Mary & George’ is coming soon to Sky Atlantic and NOW. The February issue of Harper's Bazaar is on newsstands now.