Preparation

Peel, halve and finely slice onions. Heat butter in a saucepan over low heat and cook onion for about 10-15 minutes or until lightly browned and transparent.
Add stock and stir to combine. Season with salt and pepper. Increase heat and bring to the boil. Boil for 20 minutes.
Meanwhile, toast baguette under a hot grill.
Whisk to combine the sherry and egg yolk.
Remove soup from the heat. Add sherry and egg mixture to soup, and stir to combine.
Ladle soup into four ovenproof bowls. Top each with 2 pieces of toasted baguette and scatter with cheese. Place under a hot grill for 2-3 minutes or until cheese is melted and golden brown. Take care when serving, as the soup will be very hot.

Ingredients

  • 3 large brown onions
  • 30 g butter
  • 1.5 litres strong chicken stock, approximately
  • salt and freshly ground black pepper
  • 8 x 1 cm slices baguette
  • 50 ml Xeres Spanish sherry
  • 1 egg yolk
  • 120 g tomme des Pyrénées (Pyrenees cheese), grated