A perfect French onion soup requires time. The onions need to be cooked ever so gently. But your patience will be rewarded. Here is my favorite recipe.

French onion soup is a true classic. In France, you can find it on many restaurant menus, and it is usually eaten as a starter or for lunch. I have had the pleasure of indulging in many wonderfully aromatic French onions soups, beautifully crowned with a slice of bread under a molten layer of cheese. And I’ve also had my share of disappointing onion soups. Like the one that should have been called ‘onion broth’ (there wasn’t a morsel of onion in sight). Utterly heartbreaking, especially on that cold, rainy autumn day.

But what makes an exceptionally delicious French onion soup? To me, the most important factor is time. Slowly cooking the onions is imperative in order for them to gently caramelize and infuse the broth with all of their natural sweetness. I like to cook mine for a good hour, until they are soft and enticingly fragrant. To give the soup a fine touch and extra flavor, I also add a shot of Armagnac. This is the kind of soup to make on a chilly Saturday afternoon. Perhaps after returning home from a trip to the market with a basketful of gorgeous onions. Savor it slowly, just as it was cooked. Preferably with a fruity pinot noir or beaujolais, and if you’re lucky, in front of a roaring fire.

Serves 4-6


  • 50g butter
  • 1 kilo onions, halved and thinly sliced
  • 1 clove of garlic, pressed
  • small bunch of thyme, plus 4 small sprigs for the toasts
  • 1 tsp raw cane sugar
  • salt (preferably fleur de sel) & freshly cracked pepper
  • 1½ tbsps all-purpose flour
  • 1½ tbsps Armagnac
  • 1L strong beef bouillon
  • 4-6 thick slices of sourdough bread
  •  Gruyère, freshly-grated


Melt the butter in a heavy-bottomed soup pan over a gentle heat. Add the onions, garlic, thyme, sugar and a little salt and pepper. Stir, place a lid on the pan and allow everything to cook for 1 hour. Stir occasionally. Stir in the flour and cook for three minutes. Turn up the heat, add the Armagnac and follow with the bouillon. Allow the soup to cook for an additional 10 minutes, without the lid. Taste and correct the seasoning.
To make the croutons: Put the pieces of bread on a baking sheet lined with baking paper. Top each piece with grated cheese and a sprig of rosemary. Place under a hot grill for 1-2 minutes, or until the cheese melts. Keep an eye on them so they don’t burn! Divide the soup over the bowls and top with a piece of toast.