Ask people what they think this is, and what will they say ?
Fish and Chips ?Image copyright Flickr user ordinary fool Creative Commons License
Roast Beef and Yorkshires ?
Image copyright Flickr user robbie jim Creative Commons License
Shepherd's Pie ?
Image copyright Flickr user kev walsh Creative Commons License
Chicken Tikka Masala ?Image copyright Flickr user Crashworks Creative Commons License
A "full English" ?Image copyright Flickr user Todo nada Creative Commons License
Wikipedia has a useful article on this idea with some suggestions for what the National Dishes might be.
Is it possible to narrow down a nation's cuisine to one 'signature' dish ? And don't national tastes develop in response to a whole range of outside influences anyway ?
Over to you...
And here's a useful 'listen' for you