NEW YORK Jan 25, 2006

In no particular order, here are some things Jill Hennessy loves:

Motherhood.

Comedy Central's "The Daily Show," which (along with "Sesame Street" and "Dragon Tales") is about the only TV she has a chance to watch.

The sensory delight of robust, stinky cheese.

Getting back to Manhattan, like now to publicize her TV series, "Crossing Jordan."

Hennessy is also pretty fond of "Crossing Jordan," where she plays a headstrong, sassy medical examiner whose detective work extends beyond autopsies. The NBC series, in its fifth season, airs 10 p.m. EST Sunday, and despite tough competition (like that upstart ABC hit "Grey's Anatomy") it has rounded up viewers as doggedly as Jordan tracks down killers.

"She's dysfunctional but also very strong, pro-active, comedic yet dark," says Hennessy, nibbling from a gloriously overripe cheese plate whose aromas could make Jordan's corpses stand up and salute.

At 36, Hennessy is a TV veteran. A svelte brunette with an alto voice and a larky manner, she got her show-biz start in her native Toronto doing improv comedy. But she first won notice after coming to Manhattan and landing the role of Claire Kincaid, the brainy, straight-arrow assistant district attorney on "Law & Order." She played Claire for three seasons before departing a decade ago (whereupon, in a scene that traumatized her fans, Claire died in a car crash).

Hennessy returned to series TV in the fall of 2001 after several years' success in television and theatrical films. Even so, "Crossing Jordan," which is set in Boston but filmed in Los Angeles, initially presented her with a complex mix of hopes and misgivings.

"On the one hand, you worry, `Oh, it's going to get monotonous, I'm afraid of stagnating,'" she explains during an interview at a Greenwich Village trattoria. "Then production starts, and it's a constant day-to-day evolution: `OK, what does the network want, what do the creators want, how do the actors feel?'"

Hennessy had signed on expecting a quirkier, more comic show led by Jordan as a skilled but screwball brand of heroine. She wanted "Crossing Jordan" to cross genre lines.

Instead, the series seemed drawn "down a straighter, forensic-procedural path," she recalls. "But it's always been a push-and-pull with the network. They wanted more of a `Law & Order,' `CSI' feel. And (series creator) Tim Kring wanted more character, more comedy."

She pauses to savor a bite of cheese that could upstage the fragrances in Jordan's morgue. Then she heaps praise on Kring, on her show's writers, and on her co-stars (who include Miguel Ferrer, Jerry O'Connell, Kathryn Hahn, Ravi Kapoor and Steve Valentine).

It's clearly a show she's proud of.

"But sometimes it's kind of terrifying," she admits, "because you don't know which way you're gonna go and you feel powerless. I try to contribute as much as I can, but I also realize it's not my show: I'm not the creator, I'm not the network."

Whoa! Doesn't series stardom confer a hefty dose of power?

"Not as much power as it might seem," she insists. "I think you have to force your way into that position, and I don't really want to do that.

"It can be frustrating, it can be exciting," she sums up. "It keeps you on your toes."

Also keeping her on her toes: Marco, Hennessy's son with her husband, actor-businessman Paolo Mastropietro.

Her pregnancy was accommodated with time off for her, and a shortened third season.

Then, after Marco's birth in September 2003, Hennessy was back on the set, but "nursing the baby every three hours. One of the PAs would come up and say, 'Uh, Jill, milk alarm.' I'd nurse my son and then run back and shoot a scene." She laughs. "It really brought the crew together."

Hennessy observes that "Crossing Jordan," a work in progress, retains a bit of novelty for someone whose only prior series experience was joining a show three years old with a format already set in stone when she entered the picture.

But when Hennessy and S. Epatha Merkerson came aboard in fall 1993, "Law & Order" was still struggling in the ratings. Hennessy describes with wry affection the humble state of its production facilities then as now, a converted warehouse on a Hudson River pier.

Then, amenities were spare. Like heat.

"The windows would let in cold air off the Hudson, and I remember one year right before Christmas I was in my dressing room trying to wrap presents during a break for a lighting setup. Jerry Orbach and I were fighting over this one space heater: `C'mon, Hennessy, lemme have the heater!'

"Finally, he gives in `OK, you keep it.' And I'm on the floor, trying to get as close to the heater as I can, when I feel something close to my leg. It's a mouse, huddling against my leg for warmth."

Needless to say, her career has gotten much hotter since.