The recipe
Serves 4-6
700g onions
40g butter
2 tbsp flour
1.75 litres beef stock
1 glass of white wine
Baguette to toast
Gruyère or Emmenthal
Peel and thinly slice 700g onions, then leave them to soften in 40g butter and a small glug of olive oil over a low to medium heat. Stir them regularly. They are ready when they are soft, sticky, sweet and deep gold in colour. Some add a pinch of sugar at this point to help the onions caramelise. Stir in a couple of tablespoons of flour, cook for 3 or 4 minutes, then pour in 1.75 litres of boiling beef stock and a glass of white wine. Partially cover with a lid and leave to simmer for a good 45 minutes.
Season, ladle into deep, heatproof bowls, place several thin slices of toasted baguette on to each, then cover with thinly sliced Gruyère or Emmenthal. Bake in a hot oven for 20 minutes or grill until the bread is toasted and the cheese has melted but not browned.