Best of the best French onion soup
- February 2024
- Serves 4
- Hands-on time 40 min. Simmering time 2 hours 20 min
Create the ultimate French onion soup with our masterclass recipe – read more about the magic behind it here. The umami-rich broth of homemade stock and slow-cooked onions is topped with crisp baguette and gooey comté cheese. Délicieux.
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- 25g (15g saturated)
- 28g (18g sugars)
For the stock
- 1 chicken carcass (raw from the butchers or, even better, leftover from a roast)
- 1 onion
- ½ leek
- 1 carrot
- 1 portobello mushroom
- 200ml red wine
- 1-2 handfuls veg trimmings (spring onion greens, onion tops, garlic peel, carrot peel and so on – optional)
- 10g dried porcini mushrooms
- 2 bay leaves
- ¼ bunch thyme
- ½ tsp black peppercorns
- 1-2 tsp Bovril
For the caramelised onions
- 800g onions
- 400g shallots
- 80g unsalted butter
- 100ml marsala wine or amontillado sherry
- 1-2 tsp cider vinegar
- 1 tsp Worcestershire sauce
- 4 thick baguette slices
- 1 garlic clove
- 80g comté, finely grated
- ½ bunch chives, finely chopped
- Begin with the stock. Heat the oven to 180°C fan/gas 6 and put the chicken carcass on a tray. Roast for 30 minutes until a rich reddish, dark brown – do keep an eye on it, as if you take it too far and it begins blackening it will taste too bitter and be ruined. While it roasts, slice the onion, leek, carrot and mushroom (saving any peels, roots and trimmings) and heat a dash of oil in a large stock pot over a low-medium heat. Add the sliced veg and cook until caramelised, stirring occasionally – they should be nicely done by the time the bones are ready.
- Meanwhile, finely slice the onions and shallots for the soup (again, saving the roots and peels for the stock) and add to a large, heavy-based saucepan with a lid. Put in the butter and a large pinch of salt, cover and cook over a low heat for 2 hours, stirring often, then removing the lid after the first hour. They’re ready when deeply sticky and brown – they will begin to catch quite regularly towards the end, so keep your eye on it.
- Once it’s roasted, add the carcass to the stock pot of veg, then put the oven tray over the heat and deglaze with a splash of the red wine. Scrape off the tasty bits and add it all to the pot too. Add the rest of the red wine, bring to a simmer and reduce by half, then top up with 2 litres cold water. Bring to the boil and skim off the scum/foam that rises to the top. Turn down to a simmer and add all your reserved roots, peels and any veg trimmings (if using), along with the dried mushrooms, bay leaves, thyme and peppercorns. Simmer for 2 hours or until the onions in the other pan are done.
- Strain the stock through a fine sieve into a bowl or jug – you want about 1 litre. Stir in 1 tsp Bovril: taste and add more Bovril, salt and black pepper if needed.
- Now you’ve taken the time to make these two exquisite elements, the soup itself is easy. Add the marsala or sherry to the pan with the onions and bubble for a few minutes until reduced by half. Pour in the stock and gently simmer for 20 minutes – this is just to heat through and amalgamate the flavours – it doesn’t need to reduce. Season with the vinegar, Worcestershire sauce, salt and pepper. Keep warm.
- To serve, heat the grill to medium-high and toast the baguette slices under it on both sides. Rub one side of each slice with a raw clove of peeled garlic. Divide the soup among 4 ovenproof bowls, then top with the bread, followed by lots of grated comté. Put the bowls back under the grill to melt (if you don’t own 4 ovenproof bowls, you can put the toasts on a baking tray and grill them first, then add them to the soup). Finish the dish with plenty of finely chopped chives and a generous crack of black pepper.
Don’t waste it You can make what the French call a remouillage or remi-stock with the strained stock bones and veg. Simply return them to the pan, top up with cold water and simmer again. The flavour of the second stock won’t be as strong, but adding more fresh herbs and veg helps and if you reduce it by three-quarters instead of half it will have a stronger taste too.
As the onions take so long, you may as well get the biggest pan you have and make up a double batch, then freeze half.
It’s important to add cold water when making your stock and simmer it gently. This allows the fats and impurities to rise to the top rather than emulsifying into the boiled water and making it greasy.
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