France · Soups · High protein

French Onion Soup

Name: French Onion Soup
Prep time: 26 min
Cook time: 59 min
Total time: 85 min
Yield: 4 servings
Cuisine: French
Ingredients: 6 large yellow onions; 4 tbsp unsalted butter; 1 tbsp olive oil; 1 tsp sugar; 1 tsp salt; 2 cloves garlic; 1/2 cup dry white wine; 2 tbsp flour; 2 l beef broth; 1 bay leaf; 2 sprigs fresh thyme; 1/2 tsp freshly ground black pepper; 1 tbsp Worcestershire sauce; 1 tbsp balsamic vinegar; 1 French baguette, cut into 1 cm thick slices; 2 tbsp olive oil; 2 cup Gruyère cheese; 1/2 cup Parmesan cheese

French Onion Soup is the epitome of French comfort and culinary elegance. Slowly caramelized onions in a rich beef broth, topped with toasted baguette and melted Gruyère cheese.

85 min 325 kcal 4 serves Advanced💪High protein🇫🇷France★★★★★4.6· 5 reviews

Ingredients

ServingsMetric

6 largeyellow onions
4 tbspunsalted butter
1 tbspolive oil
1 tspsugar
1 tspsalt
2 clovesgarlic
½ cupdry white wine
2 tbspflour
2 lbeef broth
1 bay leaf
2 sprigsfresh thyme
½ tspfreshly ground black pepper
1 tbspWorcestershire sauce
1 tbspbalsamic vinegar
1 French baguette, cut into 1 cm thick slices
2 tbspolive oil
2 cupGruyère cheese
½ cupParmesan cheese

Note from Sergei

Sergei Martynov

“French onion soup is a lesson in patience disguised as a recipe. The caramelization of the onions is everything — and it takes 45 minutes to an hour of slow cooking, not the 10 minutes some recipes claim. You're waiting for the natural sugars to break down and turn deep mahogany brown, layer by layer. Don't try to speed it up by cranking the heat; that gives you burnt onions, not caramelized ones. The bread and cheese crust on top isn't decoration — it's structural, turning the soup into a meal. Use real Gruyere and broil until it bubbles and blisters, with dark spots forming on the cheese.”

Deglaze the onions with a splash of dry white wine or sherry when they stick to the bottom — those brown bits (fond) are pure flavor. Use oven-safe crocks and fill the bread to the edges so the cheese seals the surface and traps the steam underneath.

Method

In a large saucepan, melt butter and olive oil over medium heat. Add the sliced onions, salt and sugar. Cook, stirring, until the onions are soft and golden, about 45-55 minutes. Add minced garlic and cook for 1 minute more.
Increase heat to medium-high and add the white wine. Scrape the brown bits from the bottom. Cook until the wine is almost evaporated, about 8-10 minutes. Sprinkle flour over the onions and cook for 1-2 minutes, stirring.
Add the beef broth, bay leaf, thyme, Worcestershire sauce and black pepper. Bring to a boil, then reduce heat and simmer under a lid for 30 minutes. Remove the bay leaf and thyme. Add balsamic vinegar if desired.
Preheat oven to 200°C. Brush the baguette slices with olive oil on both sides. Bake until golden and crisp, about 10 minutes, flipping halfway through.
Preheat oven to grill mode. Ladle hot soup into fireproof bowls. Place 1-2 croutons on top and sprinkle with a generous amount of Gruyère and Parmesan. Place under the grill for 3-5 minutes, until the cheese is melted and bubbly.

FAQ

Caramelizing onions is not just sautéing: over slow heat for 45–90 minutes the sugars in the onion slowly break down and form hundreds of aromatic compounds. Cut it to 10–15 minutes and you get soft sautéed onion — tasty, but without the deep sweet richness that defines real French onion soup. Signs it's ready: the onion has reduced to one-fifth its original volume, turned deep amber, and tastes very soft and sweet. Adding a pinch of salt at the start speeds up the process.

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Comments (2)

Злой Повар
29d ago
Карамелизация лука занимает 45 минут минимум. Не 15, как пишут блогеры, которые просто поджаривают его на сильном огне и называют это карамелизацией. Лук должен стать тёмно-коричневым и сладким, а для этого нужны тихий огонь и терпение. И гренка с сыром, запечённая до пузырей — это не украшение, это суть блюда.
Sergei Martynov✍ Author
29d ago
Bring this french onion soup to a full boil first, then drop it to the gentlest simmer your stove can manage. Aggressive boiling turns the yellow onions mushy and makes the broth cloudy. Patience here means clarity and texture.