In real life, Dolly Wells and Emily Mortimer are best friends who have known each other since they were four. One is a bit-part  actor with supporting roles in everything from The Bill to Bridget Jones' Diary. The other is a successful actor, with starring roles in everything from TV's The Newsroom to Martin Scorsese's film Shutter Island.

In Doll and Em, the TV show, they are also best friends who have known each other since they were four.  Em is established in Hollywood, preparing to headline a film, while Doll is a waitress who has just broken up with her boyfriend in London.

In tears, she calls Em, who invites her to Los Angeles to recover and work as her personal assistant. So begins Doll and Em, a delicious six-part comedy written  by, and starring, Wells and Mortimer, where fact and fiction collide as their relationship is tested as the dynamic shifts from friend to employee/employer.

That the friendship fractures is no great surprise – Em grows jealous at the ease with which Doll ingratiates herself with everyone from top producers to the crew, while Doll is sharply reminded of her new status, relegated to a spare room with another assistant during a Hollywood party – but that's not to say it's predictable.

It's sharp, funny and reminiscent of Ricky Gervais' Extras, where everyone is game (Mortimer is particularly great as she struggles to hide her age and insecurities) and Hollywood's class system is deliciously laid bare.

Mortimer has said she wanted to write a show where jealously between female friends is thoroughly explored –where friendship, while loving, has a competitive edge. On that level Doll and Em succeeds, but it's also great to see a female-led comedy, with everyone happily poking fun at themselves and the industry that employs them.

Also out on DVD

Banshee: The Complete Second Series (Warner, rated R)

Lucas Hood ( Antony Starr) is still impersonating the dead sheriff of Banshee, but just might come unstuck when his "son" arrives in town.

Boardwalk Empire: The Complete Fifth Season (Warner, rated MA)

With prohibition over and the depression biting, Nucky  (Steve Buscemi) is desperate to keep his business alive, with flashbacks showing why he can't ever be poor again.

Red Wing (Bounty, rated M)

An orphaned boy grows up in a family where secrets and suspicion cloud all, but fights to save them in spite of themselves.