Jon Favreau was thrilled to have ''established actors'' like Robert Downey Jr. on-board his new film 'Chef'.

The 47-year-old star worked alongside an A-List cast which included 'Modern Family' actress Sofia Vergara, 'Captain America: The Winter Soldier' beauty Scarlett Johansson as well as 'Iron Man' star Robert Downey Jr.

This marks Favreau's fourth collaboration with Downey - who played his alter-ego's ex-wife's first husband - who he'd worked with on the three 'Iron Man' films and insists the Hollywood hunk ''really delivered''.

Talking at the film's premiere at The Old Truman Brewery in east London, he told BANG Showbiz: ''I've worked with Robert before and it was fun to have him come on-board and whatever scenes he came in for he really delivered.

''The fact I got so much cooperation from my friends who are established actors is really helpful.''

Favreau - who was catapulted to the spotlight following his part in 1993's 'Rudy' - last hit the big screen in 2013's Oscar-nominated 'The Wolf of Wall Street' alongside Leonardo Dicaprio.

'Chef' is out in the UK on June 25.