Soupe a l'Oignon Gratinee
French onion soup, crusted with cheese
Ingredients
- 1000 g Yellow onion
- 1200 ml Beef stock
- 60 g Butter
- 1 tbsp Extra-virgin olive oil
- 1 tbsp All-purpose flour
- ½ baguette Baguette
- 200 g Gruyere cheese
- 1 tsp Salt
- ½ tsp Black pepper
- 150 ml White wine (optional)
- 30 ml Cognac / Brandy (optional)
- 3 sprigs Thyme (optional)
- 1 Bay leaves (optional)
- 1 tsp Dijon mustard (optional)
Method
- Before you turn on any heat, slice the onions thin (5 mm). That's all the prep you need right now — cheese and bread will be handled during the simmer.
- Melt butter with the oil in the Dutch oven over medium. Add onions and a pinch of salt. Cover and sweat 10 minutes to release water.
- Uncover. Raise heat to medium and cook 35 minutes, stirring every 4-5 minutes, until the onions are a deep mahogany brown (don't rush — color is flavour).
- Sprinkle the flour over and stir 1 minute. Pour in the cognac and let it bubble 30 seconds.
- Pour in the wine and reduce 3 minutes. Add the beef stock, thyme, bay leaves, the salt, and the pepper. Simmer gently 20 minutes — use this window for the cheese + bread prep below.
- While the soup simmers, grate the Gruyère and slice the baguette into 1.5 cm rounds. Set both aside.
- Still during the simmer, toast the baguette rounds at 200°C (400°F) on a baking sheet 6 minutes, flipping once, until dry and golden.
- Discard the bay leaf and thyme stems. Stir in Dijon. Taste for salt.
- Ladle soup into oven-safe bowls. Float 2-3 baguette rounds on each. Mound Gruyère on top to cover the bread completely.
- Broil on the top rack 4 minutes until the cheese is bubbling and deeply browned in spots.
- Carry to the table immediately — careful, the bowls are blistering. Eat with a spoon, breaking through the cheese cap.
Tap “Start cooking” for live timers that flag what to get ahead on while something simmers.
About Soupe a l'Oignon Gratinee
Soupe à l'oignon gratinée is the definitive French onion soup, a Parisian bistro icon whose entire character depends on one unhurried act of patience: coaxing thinly sliced yellow onions to a deep mahogany brown over the better part of an hour. That long, slow caramelization is what separates a great version from a pale one, transforming the onions' sharpness into a jammy, almost sweet richness that no shortcut can fake. A splash of cognac and white wine deglazes and sharpens the pot, while beef stock, thyme, and bay build the savory depth beneath. The finish is pure theater, a raft of toasted baguette blanketed in Gruyère and broiled until the cheese bubbles into a browned, molten crust.
Spooning through the gratinéed lid to the sweet-savory broth below is the whole point of the dish, the strands of stretchy Gruyère and rum-soaked toast giving way to onions collapsed into silk. It is warming, deeply satisfying, and unapologetically rich, the kind of bowl made for cold nights and long dinners. This version's ninety minutes is almost entirely hands-off caramelizing time, with the cheese and bread handled while the pot works, so the effort is more about attention than labor. Serve each portion in its own broiler-safe bowl so everyone gets their own cheese crust, ideally with a glass of the same wine that went into the pot.
Soupe a l'Oignon Gratinee: frequently asked questions
How many calories are in Soupe a l'Oignon Gratinee?
A serving has about 623 calories — 26.8g protein, 45g carbs, 33g fat, 5.9g fiber. Figures are estimated from the ingredient amounts and will shift with your portions and brands.
Is it high in protein?
Each serving has about 26.8g of protein, roughly 17% of its calories.
Is Soupe a l'Oignon Gratinee gluten-free?
As written, no — it contains All-purpose flour, Baguette. You'd need a certified gluten-free swap for those ingredients to make it gluten-free.
Is Soupe a l'Oignon Gratinee dairy-free?
Not as written — it uses Butter, Gruyere cheese. Swapping those for a plant-based alternative makes it dairy-free.
How long does Soupe a l'Oignon Gratinee take to make?
About 90 minutes start to finish, but only around 27 of those are hands-on — the rest is largely unattended cooking time you can step away from. In the Homecooked app the timers and parallel steps are sequenced for you so the hands-on part feels even shorter.
Do I need every ingredient to make Soupe a l'Oignon Gratinee?
The core ingredients are essential, but you can leave out white wine, cognac / brandy, thyme — they're optional and mainly there for extra flavor or finish.
How many servings does Soupe a l'Oignon Gratinee make?
This recipe makes 4 servings. In the app you can scale it up or down and the ingredient amounts adjust automatically.