Where do you get your food from, Grandma?

Where d'you get your food from, Grandma?
Though I'm grateful that you feed me a lot!

From the Biscuits to the Chocolate
To the Teabags, to the Crumpets
You have products no one else has got

In other peoples houses they have Cornflakes and KitKats
But your cupboard hasn't any of these
You give me unbranded maltflakes
And mysterious wafers and uniquely semi-circular cheese

Where d'you get your food from, Grandma?
I'm puzzled by the packets you buy
I've never seen them on TV or in any supermarket
Yet you somehow have an endless supply

Come to think of it how long has that stuff been in your cupboard?
And why do you always offer me more?
How come we never see you eating any of it yourself?
Have you been keeping it in there since the war?
Where d'you get your food from, Grandma?

Thank you!