In France simply – soupe à l'oignon
I try to keep this as simple as possible - it's a staple lunch for me - with some cheese and crackers to follow. I make large batches, usually over 3 litres (of stock) at a time. By the time the onions and wine have been added, it makes at least 10 good portions. These I bag up individually and freeze which make for a very quick lunch on a busy working day.
The followng quantities are for half that - ie 4 or 5 portions: -
1kg onions, thinly sliced
2 tbsp olive oil
1.5 litres beef stock
Half bottle white wine - I use chardonnay
The secret here is to caramalise the onions, without burning them. Place frying pan on a high heat and add the oil and butter together. When this is very hot, add the sliced onions and keep turning them from time to time until the edges of the onions have turned dark – this will take about 6 minutes. Then reduce the heat to its lowest setting and leave the onions to carry on cooking very slowly for about 30 minutes, by which time the base of the pan will be covered with a rich, nut brown, caramelised film. Be very careful that they don't catch and burn.
Whilst the onions are cooking, make the stock in a separate saucepan. Once the onions are well cooked, add them to the stock. Now you can deglaze the frying pan with the white wine, making sure all the caramelised bits and bobs that were left behind get incorporated. Pour this into the rest of the soup. You can add any remaining wine that didn't fit in the frying pan.
As soon as it all comes up to simmering point, turn down the heat to its lowest setting, then go away and leave it to cook very gently, without a lid, for about 1 hour.
Traditionally a UK 'French Onion Soup' will always come with a slice of toasted baguette, covered in melted cheese, floating on top of the soup. These have always proved awkward to eat when armed with just a soup spoon so, if I add them at all, I tend to cut the slices into manageable pieces before I add them.
Slices of french bread (as necessary). These can be toasted or fried. I prefer fried as they don't go soggy so quickly.
Once fried (or toasted), cover with grated Gruyère or Cheddar cheese and melt the cheese under the grill. Cut into bite sized pieces and float onto the soup.