• Major study by Sainsbury’s reveals the UK’s archetypal Christmas meal • The roast potato is king, it’s turkey breast over leg and we’ll each eat three and a half desserts • 77 per cent of women expect to be in charge of the cooking – but so do 45 per cent of men • Some established traditions may be in decline amongst the young, including the sprout As Britain embarks on a major festive food shop this weekend,…