Script (guión): Idioms, ‘know your onions’. If someone is well informed about something then we say they know their onions. For example, The Dog and Duck football team, which is a pub football team, have got a new manager and two of the players are talking about him. ‘What do you think of big Steve?’ says Henry.
‘Well he certainly knows his onions, he's much more technical than the last manager.’
‘Yes, he knows his onions but I'm not sure he has the same passion for the game. He reminds me of that Sven Goran Eriksson.’
‘Well, in that case, you can say he certainly knows his Swedes.’