What is French onion soup? Where to find the best of the classic French dish

THE DISH

French onion soup, France

PLATE UP

Grab your beret, your stripey shirt and your baguette: this Thursday is Bastille Day, France's national celebration, and to mark the occasion we're featuring one of that country's classic dishes, soupe a l'oignon, or French onion soup. This might, in fact, be France's most famous and ubiquitous dish (in other countries, at least), a soup based on meat stock, a little wine, and plenty of onions, which are deeply caramelised and partly disintegrate into the liquid. The whole thing is then topped with croutons and nutty gruyere cheese and "gratineed", or grilled until crisp on top and still piping hot on the bottom. Ooh la la.

FIRST SERVE

Soupe a l'oignon was invented in the 17th century by King Louis XV, who returned to his hunting lodge one night to find only onions, butter and champagne, and created something wonderful. Ha! You don't really believe that, do you? Great dishes rarely have such neat origin stories. That's something of a legend, and in fact onion soups date back to Roman times, though the modern French version was popularised in Paris's Les Halles market in the 19th century, and became widely known in countries such as the US in the early 20th century.

ORDER THERE

Go to the source in Paris, to the area around Les Halles, to taste the history of French onion soup. Try it at the venerable La Poule au Pot (jeanfrancoispiege.com), or the more affordable Au Pied de Cochon (piedecochon.com).

ORDER HERE

In Sydney this Thursday, make a booking at Loulou Bistro in Kirribilli (loulou.sydney) to sample their French onion soup "en croute". In Melbourne, head to the classy Philippe (philipperestaurant.com.au) in the CBD.

ONE MORE THING

French onion soup was first served in the US in 1861, but it truly hit the big time in 1954, when The New York Times' Food news department released a pamphlet called Soups, which featured 20 recipes, including minestrone, shrimp bisque, and French onion.

See also: The 10 famous foods that don't originate where you imagined

See also: The secrets behind the best sandwich of all time