I usually say 'I'm guessing you had salad for lunch, Amber is your best friend, you practised spellings today, you read your story about going to Legoland to your teacher' and so on. Then, when they say 'nooooo, we didn't' I ask them to give me a clue and it trickles out that way.
After years of my four children telling me they had gravy for school dinner every time I asked, I feel your pain! 
The King's Speech To Announce 'All But The End Of Leasehold System' System'


