There is a lot of truth that, in the early 1950s, these consisted of different versions of Mince, mashed Potatoes and Carrots followed by Sponge in various disguises and pale Custard.
They cost around 1shilling (5p) per day collected on Mondays by the teacher for the week. Many poor families were entitled to free dinners.
My abiding memory is watching the Dinner Lorry turn up and huge silver containers of pre-cooked food being wheeled into the kitchens.
There was always a smell of boiled Cabbage, even if this was not on the Menu.