French onion soup
French onion soup is a rich broth with caramelized sweet onions topped with toasted bread and melted Gruyère cheese. The depth of flavor develops from slowly toasting the onions, so this step cannot be replaced by quick high-heat cooking.
How to make it
Prepared 0 of 6 steps
Thinly slice the onions
Peel and halve the onion, then thinly slice it into rounds of even thickness. Prepare a heavy wide pot: in narrow vessels, this volume of onion will stay moist longer.
Caramelize slowly
Melt the butter and olive oil together, add the onion and salt. Cook on medium-low heat for 45–60 minutes, stirring every few minutes, especially at the bottom. The onions should become soft and uniformly dark golden without blackened edges.
Reduce the wine base
Sprinkle in the flour, stirring for 2 minutes. Pour in the wine and scrape up any caramelized bits from the bottom. Simmer for 3–4 minutes until noticeably reduced; the stuck-on onions should dissolve into the wine base.
Simmer the soup
Add the broth, thyme, bay leaf, and pepper. Bring to a boil and simmer on low heat for 25 minutes. Then remove the thyme sprigs and bay leaves: they have released their aroma and are no longer needed in the bowls.
Prepare the bread and cheese
Cut the baguette into slices about 1.5 cm thick and toast at 200 °C for 7–8 minutes. Coarsely grate the Gruyère. Use individual ovenproof bowls specifically rated by their manufacturer for use under a hot grill.
Broil the cheese topping
Divide the hot soup among 6 bowls, top with toasted baguette and Gruyère. Place the bowls on a tray under a preheated grill for 3–5 minutes until golden and bubbling. Take care when serving: the bowls are very hot.
Little hint
The correct color of the onion develops gradually without a large amount of added sugar. If the bottom begins to burn before the mass is soft, reduce the heat and add a spoonful of water to dissolve any stuck-on particles.
Frequently asked questions
What should I watch out for when cooking?
The correct color of the onion develops gradually without a large amount of added sugar. If the bottom begins to burn before the mass is soft, reduce the heat and add a spoonful of water to dissolve any stuck-on particles.
How should I prepare the ingredients?
Peel and halve the onion, then thinly slice it into rounds of even thickness. Prepare a heavy wide pot: in narrow vessels, this volume of onion will stay moist longer.
