Few dishes capture the essence of French onion cuisine like French onion soup, a rich, Savoury masterpiece with humble origins. Historically, onion soup dates back to ancient Rome, where onions, abundant and inexpensive, were a staple among the working class. However, it was in 18th-century France that the dish evolved into the beloved version we know today. According to legend, Louis XV is credited with refining the recipe when, late one night, he found his pantry nearly empty, save for onions, butter, and champagne. The result? A simple, comforting, and fragrant broth that soon became a hallmark in French bistros.
Ingredients:
- 3 kg of yellow onions
- 325ml bottle of port
- 325ml bottle of Madeira
- 1 litre of red wine
- 1 litre of dark chicken stock
- 1.5 litres of Veal Jus (or beef stock)
- Rosemary
- Thyme
- Bay leaves
- 20g chopped garlic
- 20g salt
- Black peppercorns
- 300g of butter
- Croutons
- 200g Grated Comté cheese
Instructions:
For the soup
- Prepare the Aromatics: Start by placing rosemary, thyme, garlic, and peppercorns into a muslin bag. Tie it securely so the flavours can infuse into the broth without leaving herbs floating in the soup. This aromatic bundle will enhance the broth and give it an extra layer of complexity.
- Caramelise the Onions: Melt butter in a large pot over medium heat. Add the julienned onions and the muslin bag. Cook the onions slowly, stirring occasionally, for about 40–50 minutes. The goal is for the onions to become golden brown and soft enough that they almost dissolve into a puree. This slow-cooking method allows the natural sugars in the onions to caramelise, creating a deep, sweet flavour. It’s important not to rush this step – the more time the onions have to cook, the richer and more intense the flavour will be.
- Deglaze and Reduce: Once the onions have caramelised beautifully, it’s time to deglaze the pot. Add the wine, scraping up any delicious caramelised bits from the bottom of the pot. Let the wine cook off, and then reduce the liquid by about 80%, allowing it to thicken into a syrupy consistency. This concentrated reduction enhances the soup’s flavour with a subtle sweetness.
- Make the Broth: Add the chicken stock and veal jus (or beef stock, if preferred) to the pot. Stir well to combine and bring it to a boil. Reduce the heat and let the soup simmer for about 20 minutes. Taste and adjust the seasoning with salt and pepper as needed. Once the broth is well-seasoned and flavorful, remove the muslin bag and discard it.
For the croutons
- Prepare the Croutons: While the soup simmers, cut the bread into large cubes or slices. Drizzle with extra virgin olive oil and spread the pieces on a baking sheet. Toast in the oven at 180°C for 6–7 minutes, or until golden and crisp. These croutons will add a lovely texture to the soup.
to Plate up
- Assemble and Gratin: Ladle the hot soup into bowls, ensuring each one has plenty of caramelised onions. Top with the crispy croutons and a generous amount of grated Comté cheese. Place the bowls under the grill or in a hot oven for a few minutes, just long enough for the cheese to melt and bubble until golden and delicious.
- Serve: Once the cheese is melted and golden, remove the bowls from the oven. Garnish with freshly chopped chives for a pop of colour and freshness. Serve immediately and enjoy the comforting, rich flavours of this classic French onion soup.
It’s very important to cook the onions well. Patience is the key. They should become almost like a puree and unrecognisable before adding the alcohol. Choose your onions carefully. Yellow onions are the best because they offer a balanced sweetness and sharpness, and caramelise beautifully.