The great French Onion Soup experiment

The great French Onion Soup experimentHaving recently organised my ever-expanding collection of recipes cut out of magazines and newspapers over the years, I realised that of all the recipes I possess, French Onion Soup recurs the most frequently, and so the great onion soup experiment was born. Deciding it would be the height of over-onionyness to try each of the recipes in turn, I vowed to find the common denominators, prune out the extraneous fripperies and create a soup that might conceivably be called ‘the ultimate’ French onion soup. Two different Nigel Slater recipes, an Anthony Bourdain bistro version and a Gordon Ramsay creation formed the basis for the experiment, with other random bits and pieces from other food writers thrown in where extra input was required.

Firstly – the onions. Nigel calls for red onions in one, white Spanish in another, Bourdain fails to specify what type of onions he uses, as does Ramsay, though the photo accompanying his recipe shows a mix of red and white in the pan. Since Nigel is emphatic about the particular sweetness and aromatic quality of Spanish onions I choose to go with that, although what a Frenchman would make of Spanish onions in his patriotic bowl I don’t know. The amount of butter the onions should be cooked in ranged from a mere 40g to the extravagant 168g, so I took the mathematical route and work out the average weight used and went for that.

I chose to break with all the core recipes and use fresh beef stock in my soup, rather than the dark chicken stock recommended by most. My justification for this is that my parents, who spent plenty of their newlywed years eating in France, both insist that it is an intense beef stock that makes the French classic superior. I also happen to always have homemade beef stock in the freezer, so it was no great chore. One Nigel Slater version suggested vegetable stock, but I can only suppose this is in order to make the dish vegetarian-friendly, rather than out of any taste consideration, as I find it a rather insipid base for soups.

My decision to use beef stock clearly affects all the subsequent aromatics. Liquids first: what alcohol to use? Suggestions included port, white wine, sherry, and cider. I was tempted by port, as I like the depth it adds, but I decided there would be plenty of that from the beef stock. White wine and cider aren’t beef’s best partners (although I’m sure they’d work well with a dark chicken-stock base) so sherry it was, or at least a close relative – Marsala. For the solids: Bourdain suggests diced bacon, and Nigel also advocates it in one recipe, but again the use of an already rich beef stock made me think twice; if I were using chicken stock I’d definitely throw in some lardons. Almost all the chefs agreed on the need for a classic bouquet garni, so in that went (parsley, thyme and bay), and though some suggested two or more bay leaves I chose to be restrained with just one small one, as an overpowering bay flavour is what ruins many a commercial onion soup. Ramsay and Nigel suggest throwing in a little flour with the sauteing onions, but I like my soups clear and unthickened so that idea was out. Finally, onion soup isn’t truly French unless it has cheesy croutes floating on top, and this was the one point on which ALL the recipes agreed – the bread has to be a sliced French baguette and the cheese has to be Gruyère. Traditionally one would lightly toast the bread, float the croutes on top, cover with cheese and then pop under the grill, but I found it much easier to grill the croutes on their own, then float them on top of the soup just before serving – easier to do under a teensy domestic grill, and it also helps avoid the pitfall of them disintegrating en route from kitchen to table!

The result?  A rich, intensely savoury soup to warm the cockles of your heart.  One for cold crisp days when all you want to do is curl up on the sofa and keep warm.

The great French Onion Soup experiment

Ultimate French Onion Soup – serves 4


  • 65g butter
  • 3 large white Spanish onions (approx 900g), finely sliced
  • 3-4 tbsp Marsala
  • 1.2litres fresh beef stock (bouillon powder, cubes or concentrate will NOT do here!)
  • Bouquet garni (fresh sprigs of thyme, a small bay leaf and fresh parsley tied in a piece of muslin)
  • 8 slices of baguette (French, naturally)
  • A handful of Gruyere, grated


The great French Onion Soup1. Get a large heavy saucepan or casserole dish quite hot and throw in the butter with a tablespoon of oil, let it melt and start to bubble before adding the sliced onions and a pinch of salt (the salt helps the onions release their moisture quickly, preventing them from burning too easily).

2. Be patient! Let the onions The great French Onion Soup experimentcook slooooowly over a medium-to-low heat until they are golden and caramelised (allow at least an hour, maybe more if using something really thick-bottomed like a Le Creuset). Let them have a little longer than you think they’ll need – you should be getting concerned that there’s not enough in the pot to feed everyone – before you continue. Try not to poke them more than is necessary and only move on to the next stage when the bottom of your pan is getting seriously sticky with semi-crisp, caramelised oniony bits.

3. Splash in 3 tablespoons of the Marsala (or for a non-alcoholic version, sherry vinegar). Scrape the bottom of the pan with your wooden spoon or spatula, so that you get all of the goodness off before it burns. Add the stock (room temperature or hot, not fridge-cold!) and the bouquet garni.

4. Give everything a good stir, season generously with pepper (don’t go too heavy on the salt just yet), partially cover with a lid and bring just up to the boil, then turn right down to a bare simmer and leave it to bubble undisturbed for 30 minutes. Taste and adjust the seasoning just before serving – as well as salt & pepper it may need that last tablespoon of Marsala to ‘lift’ the flavours.

5. Lightly toast the baguette slices The great French Onion Soup experimentand ladle the soup into bowls (make sure they are sufficiently heat-proof if you plan to grill the croutes in-situ). Top the now toasted baguette slices with the grated cheese and pop under the grill until golden and bubbling. Alternatively, float one or two baguette slices on top of each soup portion and sprinkle on the Gruyere. If you can only fit on one, keep the other slice(s) aside, topped with cheese, and serve at the table. Grill until browned.

6. Finally – serve. The soup will be incredibly hot so be careful. This makes a suprisingly substantial supper, so you shouldn’t need any accompaniment.

2 thoughts on “The great French Onion Soup experiment

  1. That is terrific! A perfect old fashioned ruby wood and leather colour, I can nearly taste it. I made this soup only once (at the request of our nonagenarian neighbour) during the three years we lived in France but I now crave it, and other things gallic. Which I suppose raises the question: are we nostalgic for France itself or for our idea of France? Hmmm…

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