Writing is like breathing to me, says Hollywood's queen of fiction Shonda Rhimes

Rhimes was, she recalls, often the only black girl in her class. And she had difficulty making friends. It seems an incongruous start for a screenwriter-turned-producer who now owns a stable of Hollywood's biggest hits: Grey's Anatomy, Scandal and How To Get Away With Murder.

"It was an interesting path," the 47-year-old writer/producer says. "I don't know if I would change it for anything."

What is more, she adds, it was the solitary mind of that childhood, where she was forced to create imaginary friends, and inhabit fictional narratives, that ultimately gave her the tools to become a storyteller.

"There's no way that I would probably be doing what I was doing if I was a kid who spent all of her time playing with tons of friends, instead of spending all my time in the pantry, playing with cans and magical things," she says.

"I definitely preferred reading, I definitely preferred spending my time alone," she adds. "I think that's who I was and my imagination was definitely grown that way."

Later there were more conventional touches to her biography: writing for her college newspaper and directing student theatre productions while studying English and film studies at Dartmouth College.

In Hollywood her first hit was Grey's Anatomy in 2005, now into the second half of its second decade on air. It was followed by a hit spin-off Private Practice and, aside from a false start with Off The Map, more hits in Scandal and How To Get Away With Murder.

Those shows, along with her new series The Catch, now reside under the banner of her production company ShondaLand. And that company effectively places her among television's most successful producers, a pantheon that includes Aaron Spelling, Dick Wolf and David E. Kelley.

Her success is a significant milestone in levelling of the Hollywood playing field to include women and people of non-white backgrounds. At the same time, Rhimes steps through the politics of gender and race carefully, aware that every observation is subject to excessive analysis.

Her gender and race were not, she says, obstacles. "Because I've never been any other gender or any other race," she says simply. It might warrant further debate but Rhimes has, in her voice, a tone of closure.

She also does not consciously write political or social commentary into her programs, expressing surprise that people find both there. It's possible the audiences focus on that is a reflection of their own concerns, she agrees. But it's equally possible she's writing it, even unconsciously.

"It's just that I'm not purposely going, I'm going to write about this this week," she explains. "We are having conversations in the room about the stuff that I can't get out of my head and that's the stuff that ends up on the screen or in the scripts. There's very rarely a time when I thought, let's do this issue. That feels very boring to me."

Equally she is ill at ease being asked about what's in the sausage – to lean on an old analogy for the making of television series – that is so successfully poured into ShondaLand's sausage casings.

"Everybody always wants me to comment on the creative process, [but] I'm very dedicated to not examining the creative process," she says. "Because if I examine the creative process I would not be able to do it."

For Rhimes the mantra is simple: "I write about what I want to watch." But for the student writer hoping to extract from her anything more substantial or specific, disappointment awaits.

"It changes," Rhimes says. "If I'm passionate about it, if I can't get it out of my brain. I have a very varied palette of things I'd like to watch. It just has to be well-told and interesting."

Her method is very hands-on: she often writes in isolation, with headphones on, and sequesters herself away working on scripts. Some shows, such as The Catch, have their own writing staffs. But others, such as Grey's Anatomy and Scandal, are still closely supervised by their creator.

Storytelling is, she agrees, something of an involuntary muscle. But Rhimes draws a line between writing and work. "Those are two different things, as far as I'm concerned," she says. "Writing is just breathing and work is the shows. It's two different things."

And a world without either scarcely bears thinking about. "I fantasise about that a great deal," she says, smiling. "If there really was no work to be done, there was nobody who was going to email me, there was actually nothing that had to be done, I can't even imagine what that would be like. It sounds amazing."