Kat Dennings says working with Natalie Portman was a dream come true.

The 'Thor: The Dark World' actresses have been close friends for many years and were ecstatic when they finally got the opportunity to star alongside each other in the big budget superhero sequel.

Speaking to BANG Showbiz at the film's world premiere in London's Leicester Square on Tuesday (22.10.13), Kat said: ''We've been friends a long time before the film and we've talked about getting to work together and it finally happened with 'Thor'. It was so much better than I ever hoped.''

Both Natalie, 32, and 'Thor' leading man Chris Hemsworth, 30, have had children since filming the first movie in the superhero series and Kat has enjoyed seeing their transformation into doting parents.

The 27-year-old star added it is ''beautiful to see them with their families'', referring to Natalie's two-year-old son, Aleph, with husband Benjamin Millepied, and Chris' 18-month-old daughter, India Rose, with wife Elsa Pataky.

Kat also stars on hit US sitcom '2 Broke Girls' - which was created by Michael Patrick King, the brains behind 'Sex and the City' - but she admits she hasn't nudged her Oscar-winning pal to make a guest appearance.

She said: ''I haven't asked her. That might be a little too meta for '2 Broke Girls'.''