Every culture has its traditional foods, some prepared for centuries, others made for several generations or simply passed down within families. This is why many traditional recipes have a multitude of variations and every family 'knows' that their version of the dish is the best one. Sometimes foods can embed themselves into a culture in a relatively short period of time (consider British adoption of chili con carne, spaghetti bolognese or chicken tikka masala) that they become considered to be 'traditional' foods. Which does mean that calling something 'traditional' can be more than a bit of a judgement call. Foods also fall out of favour, so a dish that's never or hardly ever prepared any more can still count as a traditional dish