Soupe à l’Oignon

Main Course

Soupe à l’oignon is the ultimate French comfort food, rich, golden broth brimming with caramelised onions, crowned with bubbling cheese and crisp baguette. Whether you’re chasing away a chill, or a hangover, this dish does the job deliciously every time.

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Prep Time 20 minutes mins

Cook Time 50 minutes mins

Total Time 1 hour hr 10 minutes mins

Servings 4

Ingredients 

1x2x3x?

• 750 gr onion
• 75 gr unsalted butter
• 2 l vegetable stock
• 125 ml dry white wine (for example a Domaine Fournier Les Belles Vignes Sancerre Blanc 2023)
• 1 baguette
• 200 gr Comté cheese (or Gruyère or Emmental)
• 1 thyme (optional, for aroma)
• 1 bay leaf (optional, for aroma)
• salt and black pepper

Equipment

• 1 dutch oven
• 1 wooden spoon
• 1 knife
• 1 chopping board
• 1 grater
• 4 ovenproof soup bowls
• 1 baking tray

Instructions

1. 1. Prepare and caramelise the onions

   Peel and finely slice the onions. In a large saucepan over a gentle heat, melt the butter. Add the onions and a generous pinch of salt. Cook slowly, stirring often, until the onions are soft, golden, and deeply caramelised, this can take 30 to 40 minutes. Don’t rush this step is the soul of the soup.
2. 2. Build the base

   Pour in the white wine to deglaze the onions, and allow it to bubble away, scraping up any sticky bits from the bottom of the pan. Add the stock, thyme, bay leaf, and a pinch of nutmeg. Bring to a gentle simmer, cover, and cook for 20 minutes so the flavours meld together. Season with salt and pepper to taste.
3. 3. Prepare the bread

   While the soup simmers, preheat your grill (or oven at 200°C). Slice the baguette into thick rounds and toast them on a baking tray until golden. Generously top each slice with grated cheese and return to the grill until the cheese is bubbling and golden.
4. 4. Finish and serve

   Remove the thyme and bay leaf from the soup. Ladle the hot soup into ovenproof bowls. Float a few cheesy croutons on top of each bowl, and if you’re feeling indulgent, scatter over a bit more cheese and pop the bowls under the grill for a few minutes until the top is gloriously gratinéed. Serve immediately, piping hot and bubbling.

Notes

• Really take your time caramelising the onions. The deeper the colour, the richer and sweeter your soup will taste. If you rush this bit, you’ll miss out on that classic, almost jammy depth that makes French onion soup so special.
• If you’re feeling a little rebellious, try a mix of Gruyère and Comté for the croutons. The blend gives you that perfect balance of melt and tang.
• Day-old baguette works best for the cheesy croutons. It holds up beautifully in the soup and soaks up all that savoury broth without falling apart.
• If you’re making this ahead, the soup itself keeps brilliantly in the fridge for up to three days. Just add the cheesy croutons fresh when you’re ready to serve.

About this recipe

Soupe à l’oignon is the ultimate French comfort food, with roots stretching all the way back to Roman times. Once known as “the soup of the poor,” it was beloved for its humble ingredients, onions, bread, and cheese, making it a staple for workers and night owls alike. Legend has it that Louis XV himself whipped up a version with nothing but onions, butter, and champagne after a late-night hunt, while others claim the Duke of Lorraine was so smitten with the soup at a Champagne inn that he demanded the recipe on the spot.

The version we know and love today, with its bubbling cheese and crusty bread, became a Parisian classic in the markets of Les Halles, where it was famed for reviving late-night revelers and newlyweds alike. In fact, it’s still a tradition in some French weddings to serve soupe à l’oignon after midnight, supposedly the perfect cure for a little too much celebration. Whether you’re chasing away a chill, a hangover, or just a bout of nostalgia, this soup is French hospitality in a bowl, simple, generous, and endlessly comforting.