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French onion soup with browned melted cheese and bread.

Soups & potages

Soupe à l’Oignon Gratinée

By Nagi Maehashi

Deeply golden onions give this soup its sweetness and savoury depth, with a crisp cheese toast ready to soak up the broth. Butter, good stock and patient cooking do the work. Nagi Maehashi grills the bread separately, so it reaches the bowl with melted Gruyère and a little crunch still intact. Break through the cheese with your spoon and let the toast catch the rich onion juices.

Prep
20 min
Cook
1 hr 30 min
Total
1 hr 50 min
Serves4–6
Nutrition
Jump to recipe ↓RecipeTin Eats ↗

Ingredients

Soup

  • Alternative

    3 fresh bay leaves in place of 2 dried bay leaves.

Cheese toast

  • Alternative

    100 g mozzarella or another melting cheese in place of 100 g Gruyère.

Method

  1. Melt the butter in a heavy casserole over medium heat. When it foams, add the onions and stir to coat.
  2. Lower to medium-low and cook 30 minutes, stirring every few minutes, until softened and translucent.
  3. Increase to medium or medium-high, add salt and cook another 20–30 minutes, stirring more frequently, until the onions are deep golden and sweet.
  4. Add the optional wine and simmer rapidly for 2 minutes, scraping the base, until mostly evaporated.
  5. Sprinkle over the flour and cook 1 minute.
  6. Add the stock, thyme and bay. Cover, lower the heat and simmer gently for 30 minutes.
  7. For the cheese toast, heat the grill to high and toast both sides of the bread until light golden. Top with the cheese and grill until melted with brown spots.
  8. Season the soup with salt and pepper, ladle into bowls and add one or two cheese toasts. Add the optional herb garnish.

Equipment

Heavy casserole; Grill; Baking tray

Notes

  • Onions: halve and slice from top to bottom to help them keep their shape. Give them time to become deeply golden, stirring more often as they colour. A wider pan works faster; Nagi’s 24 cm pot took almost an hour.
  • Stock and wine: use good-quality low-salt stock. Chicken or vegetable stock is preferable to a poor beef stock. The wine is optional, since stock will also lift the browned juices from the pan; if using wine, choose a dry, non-woody one.
  • Cheese toast: choose bread with a soft crumb that you can cut through with a spoon. Grilling the toast separately avoids the need for ovenproof bowls and keeps it from becoming too soggy. Gruyère, mozzarella or another melting cheese will work.
  • Slow-cooker onions: toss the original batch of onions with 30 g melted butter and cook on LOW for 10 hours. Transfer to a large pan with another 30 g butter and some, rather than all, of the slow-cooker juices. Cook for 10–15 minutes until deeply caramelised, then continue with the soup. Use these alternative butter quantities in place of the standard 100 g.
  • Making ahead: Nagi confirms that the soup freezes well. Prepare the cheese toast separately when you are ready to serve.
  • Portions and nutrition: the original batch serves 4–6. Published nutrition is an estimate for one of six 435 g portions and stays fixed when you scale the batch.

How to

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Photos

7 photos
How to make French Onion SoupSteps 1–8 · OverviewMaking the soup and cheese toastClose up of Caramelised Onions in a potStep 3Deeply caramelised onionsHow to make Slow Cooker Caramelised OnionsStep by step · OverviewThe source’s slow-cooker onion alternativePot of French Onion Soup, fresh off the stoveFinished dishThe finished onion soupClose up of French Onion Soup with cheese toastServingOnion soup with Gruyère toastClose up of French Onion Soup being ladled out of potServingCheese toast over the onion brothClose up overhead photo of French Onion Soup in a white bowl with a spoonServingA bowl of onion soup

Soupe à l’Oignon Gratinée

Recipe photos

About this dish

Onion soup is woven into the story of Les Halles, the old central food market of Paris. Street sellers served it to traders and shoppers before it found its way onto the menus of neighbouring restaurants. By the middle of the nineteenth century, the gratinée des Halles had become an emblem of the city’s nightlife, a warming bowl for a district that worked and ate through the night.

Nagi Maehashi gives equal billing to the caramelised onions and the cheese toast. A great mound of onions slowly collapses into a deeply golden base, with the browned juices lifted from the pot by wine or stock. This is where the soup acquires its sweetness and depth. She grills the cheese-covered bread separately, partly because she has no use for storing special soup bowls, but also because she prefers the bread with a little texture left. It is a practical variation on the gratinée that keeps its generous spirit.

Recipe and cooking notes adapted from RecipeTin Eats.