Humphrey Carpenter 
Mr Majeika and the Dinner Lady 

Mr Majeika is the most magical teacher around!
»Sometimes, » whispered Jody. »I think school dinners would be all right if it wasn»t for her.»
Mrs Chipchase, the nasty dinner lady, makes lunch hour at St Barty»s really unpleasant. That is, for everyone but her »favourite friend», Hamish Bigmore. Up to his usual tricks, Hamish is allowed to eat chocolate instead of ghastly school dinners!
Mr Majeika decides it»s time to sort out the menu in his most magical way…!
There are lots more Mr Majeika adventures to collect, including:
Mr Majika and the Ghost Train
Mr Majeika and the Lost Spell Book
Mr Majeika and the Haunted Hotel
Mr Majeika and the School Play
Mr Majeika and the School Trip