Forget Les Halles, forget Paris; this is the ultimate soupe à l’oignon. Whenever I order onion soup in a Parisian bistro, I taste, I savour and I always end up saying ‘Close, but not a patch on yours, sweetheart!’ This soup is rich, intensely flavoured and one of Helen’s signature dishes, always eliciting swoons of delight whenever she makes it. Some of our friends have even tried to pre-order it.
Slow cooking is the secret. Don’t try to rush, and always make double the quantity you think you’ll need; it freezes really well and you’ll be able to treat yourself at the drop of a hat.
A cheese-laden crouton is the decadent final touch; a light red wine such as a Fleurie, gently chilled, is the perfect match. In France, diners have been known to swill out their bowls with wine to eke out the very last drop. And why not?
- For the soup
- 1.5kg onions, peeled, cut into quarters vertically and sliced 5 – 7 mm thick
- 4 tablespoons of olive oil for frying
- 2 tablespoons of plain flour
- 2 teaspoons of sugar
- 1 tablespoon of Dijon mustard
- 1.5 litres of good chicken stock or 2 chicken stock cubes made up with 1.5 litres of boiling water
- Salt and freshly ground black pepper
- 50 ml Cognac or brandy (nothing too good, unless you’re drinking it while cooking)
- 1 tablespoon of cornflour mixed with a little cold water
- For the croutons
- 6 slices of baguette
- Olive oil for frying
- 150 g Gruyère or Emmenthal, grated, mixed with 25 g of finely grated Parmesan (although you can use Cheddar at a pinch). You can omit the cheese to keep things kosher.
- Add the olive oil to a heavy-based frying pan and sweat the sliced onions gently and slowly until they have completely softened, but not browned. This may take some time (30 – 40 minutes), but do not rush and burn them.
- When they have softened, sprinkle over the sugar.
- Turn up the heat a little and continue to sweat the onions until they turn a deep golden brown, stirring occasionally to prevent them from sticking.
- Sprinkle over the flour and stir it into the onions.
- Add the stock and bring the soup to a boil.
- Turn down the heat, stir in the mustard and gently simmer for about 30 minutes.
- The thickness of the soup should be somewhere between that of milk and single cream. If it seems too watery, stir in the cornflour and water mix a little at a time until the correct consistency is achieved.
- Season with ½ teaspoon of salt and ¼ teaspoon of black pepper. Adjust to taste.
- Add the brandy and simmer for 5 more minutes. (Or if you prefer, you can put a teaspoon into each bowl before you ladle in the soup for a more punchy flavour.)
- While it simmers, start the croutons by frying the slices of baguette in olive oil until golden brown on both sides.
- Place a crouton in the bottom of each bowl, heap with grated cheese (if using) and ladle over the hot soup to melt it. If you have suitable bowls and enough oven space, fill the bowls with soup first, float a cheese-laden crouton on top and grill until the cheese is melted and bubbling.
- A word of caution: this onion soup freezes well but otherwise does not keep; because of its sugar content it tends to ferment very quickly. If you’re making it more than 24 hours in advance, allow it to cool and then freeze it until it is required.