It is the fashionable cooking technique favoured by many MasterChef contestants.
But now Government scientists have found the 'sous-vide' method of simmering vacuum-packed foods in a water bath could increase the risk of food poisoning, reported the Daily Mail.
Tests showed that water temperatures in sous-vide cooking were too low to kill potentially deadly bugs such as salmonella, E.coli and campylobacter.
Experts from Public Health England analysed 34 meals from restaurants, hotels and pubs which were mostly made up of chicken or duck breast cooked in a water bath.
The results, in the journal Epidemiology and Infection, showed ten had 'unsatisfactory' levels of bacterial contamination and another eight were borderline.