Although we tend to think of slow cookers as a relatively new ‘best friend’ to the home chef, the first one appeared in 1940 introduced by an American, Irving Naxon. He was inspired by his mother’s stories of preparing a Jewish bean-based stew in her home country of Lithuania. She would start the cooking on the Friday, and at the beginning of the Jewish Sabbath that night — a time of rest — the ovens would be turned off and the residual heat would continue to cook the beans for hours until the end of Saturday services.

Irving sold his patent for his ‘Naxon Beanery’ in 1970 to Rival Manufacturing who renamed it the Crock Pot and sales soared. However, with the introduction and success of microwave ovens in the 1980s, many Crock Pots were relegated to the back of the kitchen cupboard.

Design revamps, including removable inner ‘casseroles’ — something the Crock Pot lacked — has greatly boosted interest and triggered the sales of millions of slow cooker recipe books.

Very little moisture is lost from slow cookers, so if you're using a favourite casserole recipe, reduce the amount of liquid by one-third to one-half.