07/30/2007 at 11:00 AM EDT
A "dream" opportunity lured Gwyneth Paltrow
away from her two kids and back to the big screen this year.
Coming out of mommy retirement for Iron Man
was easy, Paltrow said, given the chance to costar with Robert Downey Jr. (She plays his assistant, Virginia "Pepper" Potts in the comic book brought to life.)
Working with Downey "has always been a dream of mine," said Paltrow, 34, who also admitted her previous knowledge of comic books was limited to "my brother's Underoos in 1982."
Playing assistant to a super hero seems to have given Paltrow super strength. The actress – on the mend from recent knee surgery – sported a pair of vertiginous silver heels to promote the flick at Comic-Con in San Diego Sunday.
"Don't show my non-orthopedic shoes," Paltrow joked to reporters. "I got off the crutches two weeks ago and the cane yesterday and I've been doing a lot of physical therapy and I'm seriously not supposed to be in these shoes, but that's okay."
Paltrow began shooting Iron Man
in April – after a full-blown body assault.
"I was like a post-baby nightmare," she says of her shape when son Moses was born on April 8, 2006
(daughter Apple is 3). "So I worked really, really hard. I had an amazing trainer and I worked out twice a day and did dance cardio and felt like a complete nerd and I just really worked hard. I got into shape. And there you go. I was ready to go."
"It was great for me to have that break," she added of her time off from work. "I really needed that break and I've come back to the whole world with such an appreciation for it."
Reporting by SCOTT HUVER