John Krasinski cooks for his wife Emily Blunt "once a week" after he lost a bet.

Speaking about why he is starting to spend more time in the kitchen on the ABC chat show 'Jimmy Kimmel Live!', he said: "We made a stupid bet and I lost.

"The bet was Emily said something about Leonardo DiCaprio being 41. And I said, 'How dare you! That cherub of a man - that cherub of a talent - can't be more than 28.' He's not over 40, was my thing. She said, 'If I'm right, you have to cook for me every Sunday. And if you're right, you get to play 'Call of Duty' once a week.' So I thought, 'Here we go! This is the good stuff.' He's 41."

John credits himself with excellent culinary skills after he perfected a roast dinner for Emily - with whom he has daughters Hazel, two, and two-month-old Violet - to celebrate Mother's Day, although it has taken him his whole life time to learn to cook.

He explained: "I actually just started cooking. It only took me 36 years to learn how to cook for myself.

"Cooking started as a Mother's Day gift to Emily. It's pretty sad that that's what impresses her. That just goes to show you how unimpressive I am at home that I was like, 'I'm going to cook you a meal,' and she was like, 'Oh, my God!' So, that was my Mother's Day gift to her.

"Because she's from England--they do a lot of roasts over there - I said, 'I'm going to do a roast.' It was really sweet because my wife said, 'What are you going to cook?' and I said, 'A roast.' I saw her [scowl] and I said, 'Why? What's wrong?' She goes, 'It's really difficult. You should do something else.'"

"I made one mean roast!"