French onion soup is a classic French soup. It's lightly bound with a little flour.
For the soup:
- 4 large onions
- 1 liter of beef stock (use home made onion stock to make a vegetarian soup)
- 1 tbsp of flour
For the croutons:
- Slice the onions into rings and sauté them gently in the butter (don't use olive oil for this). Don't rush this, let the onions brown very gently. If some brown bits appear on the bottom of your pan, don't worry, these are the sugars from the onions that have caramelized. They'll dissolve when you add the stock.
- Add the flour and stir. The flour will seem to have disappeared, but has been absorbed into the butter. This will give the soup its characteristic slight thickness.
- Add a quarter of the stock and stir for a while. Add another quarter of the stock and keep stirring. Repeat for the remaining stock.
- Crush and chop the garlic. Put the olive oil and butter into the pan and lightly sauté the garlic.
- Increase the heat a little and fry the slices of bread until golden.
Serve the soup with the croutons floating in it.
Notes, tips, and variations
- Described here is only one way to make the croutons.
- Onion soup is often eaten with grated cheese (Gruyère, classically). It can be sprinkled over oven-baked croutons or sprinkled over the soup when the croutons are already baked.
- You may find it useful to substitute a wok for a frying pan, as the higher sides make it easier to avoid spilling the soup after adding the stock.