Most countries have a dish that stands for them abroad. That status is rarely the result of the dish being the most eaten or the most old, and something chose it.
Nation building needs edible symbols
States assembling a national identity from distinct regions need shared references, and food is among the most accessible. A dish can represent a country without excluding anyone by language or region.
Official promotion follows, through school curricula, state banquets and tourism material. Repetition in those settings establishes the association quickly.
The chosen dish is frequently from one region rather than all of them. Which region held political influence at the moment of selection usually explains the choice.
Restaurants abroad do the heavy lifting
Migrant communities open restaurants, and those restaurants must present a legible identity to customers who know little about the country. A simplified menu results.
Dishes that travel well dominate that menu. They need ingredients available locally, a form that survives a commercial kitchen, and flavours a foreign palate accepts readily.
The version that becomes famous abroad is therefore adapted. It can differ substantially from anything commonly eaten at home, sometimes to the irritation of visitors from the country.
Tourism boards standardise the story
Promotional material needs a short answer to what a country tastes like. Marketing selects one dish and repeats it, which crowds out the alternatives.
Certification schemes and protected designations formalise this further by defining an authorised recipe. A living regional variation becomes a legal specification.
Those definitions have real economic consequences, protecting producers and excluding others. Disputes over them are commercial as much as cultural.
Ingredients are often recent arrivals
Many defining ingredients reached their adopted cuisines through trade within the last few centuries. Chillies, tomatoes, potatoes and maize all crossed oceans before becoming inseparable from particular national cooking.
The adoption was fast where the ingredient suited the existing technique. It replaced a local equivalent rather than creating a new dish from nothing.
Claims of ancient continuity therefore need care. The technique is often old and the ingredient list frequently is not.
Rival claims across borders
Dishes cross frontiers freely and are claimed on both sides, particularly where borders were drawn through culinary regions. Disputes over origin are common and rarely resolvable.
The honest answer is usually that a shared region developed a shared food before either state existed. National attribution came afterwards.
For a traveller, the useful move is to eat the regional versions rather than the national one. The variation between valleys is more informative than the version on the tourism poster.