With own Marvel series, Kathryn Hahn at peak of her powers

Kathryn Hahn has a theory about people. “I call them blooming onions,” she says. “There are so many layers. To peel what’s going on under those layers is a wonderful thing.”

She likes to peel apart fictional characters in the same way. And there are many of those in the future for the beloved character actor in the midst of what’s been described as a Hahnaissance.

Take her fan favorite role as campy ancient witch Agatha Harkness from “WandaVision” who now helms her own Disney+ series.

“I love this part so much because this is a woman whose layers of defense were built up over centuries. She looks fabulous, but she’s not young,” the 48-year-old Hahn says. “To see what’s driving her and go deeper, well, that’s the stuff to chew on in life and as an actor. It gets my heart racing.”

In “Agatha All Along,” debuting Wednesday, Hahn reprises her role as the powerful witch, one of the original victims of the Salem witch trials. She must recruit some unusual allies on her quest to regain the powers she lost when Wanda cast a spell to trap Agatha in the fictional town of Westview. Patti LuPone, Aubrey Plaza and Joe Locke also star.

“We always joked that it would be so annoying to Agatha Harkness to not have her own fricking show,” Hahn says. “And now she has one.”

Hahn is married to actor Ethan Sandler (“Crossing Jordan”), whom she met in college. They live in Los Angeles with their children, Leonard and Mae.

Her good life tips:

Unfinished business

Hahn thought she might be done with Agatha after “WandaVision,” but then writer/showrunner Jac Schaeffer told her, “God, I’d love to write for you again. We both kept saying we had unfinished business at the end of ‘WandaVision.’ It could have meant this world or another one, but the point is our minds melded. And I wasn’t done with Agatha either.” What does she like the most about this witch? “I love her point of view and sense of humor. So, the point is it’s good to revisit unfinished business.”

Marvel at it all

She was in Serbia shooting “Glass Onion: A Knives Out Mystery” when she got the call: “‘How’d you like your own Marvel show?’ My heart was pounding,” Hahn says. On the “Agatha” set, someone put a sign in her trailer window that read: “Welcome to the first day of your very own Marvel show.” “I burst into tears,” she says.

Being witchy

Hahn says that she “has a ball” with Agatha, who can often be found winking, cackling and singing.

How does she catch those anything-goes vibes? She says that the “Agatha” set in Georgia got her in quite a witchy mood.

“We’d have this circle together between takes,” she shares. “It really felt like a coven around a caldron. You could her the cackles. It was so immersive as an actor. … You didn’t have to shake off the outside world because you really focused and it felt very witchy, very connected to the earth and right there. It was helpful and very trippy.”

‘Little nuggets’

She says that working with Plaza, who plays a new witch, was a plus since the two became no-holds-barred friends. “We knew each other socially, but we didn’t really talk about it much,” Hahn says.”Instead, we embraced this moment and sent songs and pictures of the moon to each other to get in that witchy mood. These were little nuggets. We were nugget-ing back and forth like good friends do.”

Stay open

Hahn doesn’t fret aging. “You just have to stay open to the way the chapters in your life work through you,” she says.

Be still

Hahn says that she learned one of her best life lessons on the set of her TV series “Crossing Jordan.” “Miguel Ferrer taught me about the power of stillness and that to do less is usually the most powerful thing,” she shares. “There is a power in listening.”

Unwind and organize

Hahn says her relaxing tips include simple things like doing the laundry for her family or organizing a closet. “I love to purge stuff,” she says. Next step: Sell it or donate it. “I would love to be a professional closet organizer,” she says. Another way that she deals with stress is by staying off social media. “I’m a technophobe,” she says.

Dream scenario

She also gets plenty of sleep for rest and resolution. “I look forward to my dreams as a continuation of my creative work,” Hahn says. “A lot of powerful stuff happens when we sleep. If you set an intention that you’re going to try to resolve something or ask a specific questions, the answer might be in your dreams.” To start her day stress-free, she makes a gratitude list.

Keep moving

“Life is a Ferris wheel,” she says. “You might go up. You might go down. You’re just always moving.”