4 oz unsalted butter
Maldon sea salt
1 ½ teaspoons plain flour
beef stock (see recipe)
sherry wine vinegar
extra virgin olive oil
Maldon sea salt
lots of grated Gruyere or Emmenthal
- Cut off the tops and bottoms of the onions, then cut the onions lengthwise in half. Remove the skins and tough outer layers and slice thinly. (Alternatively – and to avoid an ocean of tears – slice in a food processor).
- Melt the butter in a large heavy saucepan over a low heat. Add the onions and 1 tsp salt. Cook stirring every now and again and regulating the heat to keep the mixture bubbling gently, for about 1 hour, or until the onions have wilted and released a lot of liquid. Continue to stir the onions every 15 minutes being sure to scrape the bottom and corners of the pot, for about 3 hours or until the onions are caramelised throughout. Remove from the heat.
- Transfer the caramelized onion to a 4.5 litre saucepan. Sift in the flour and cook over a medium-high heat, stirring for 2 to 3 minutes. Add the beef, veg or chicken stock, bring to a simmer, and leave to blip away for about 1 hour or until the liquid is reduced to 2 litres. Season to taste with salt, pepper and a few drops of vinegar. Remove from heat and if you can be bothered, leave overnight for the flavours to marry.
- Preheat the grill. Cut 12 3/8 inch thick slices from the baguette and place on a baking sheet. Brush the bread lightly on both sides with olive oil and sprinkle lightly with salt. Place under the grill and toast the first side until golden brown then turn and brown the second side. Set aside and leave the grill on.
- Return the soup to a simmer. Place six flameproof soup bowls, with about 1 ½ cups capacity on a baking sheet to catch any spills. Add the hot soup to the bowls and lay the cheese on top.
- Place under the grill for a few minutes until the cheese bubbles, browns and forms a thick crust. Serve with the croutons and a salad.