Red onion soup and cheese toasts recipe

(815 ratings)

Red onion soup with melting cheese toasts

  • healthy
Cooking Time1 hours 20 mins
Cost RangeCheap

This red onion soup is tasty enough already but the melting cheese toasts really top it off!


  • 30ml (2tbsp) sunflower oil
  • 15g (1/2oz) butter
  • 650g (1lb 7oz) small red onions, peeled and thinly sliced
  • 10ml (2tsp) sugar
  • 15ml (1tbsp) plain flour
  • 10ml (2tsp) wholegrain mustard
  • 1.2 litres (2pt) beef or vegetable stock
  • 2 large sprigs fresh thyme
  • 8 thin slices French bread
  • 50g (2oz) Gruyère cheese
  • Fresh thyme leaves, to garnish




  1. Heat the oil and butter in a large deep pan. Add the onions and cook gently over a low heat for 10 mins, stirring frequently. Sprinkle over the sugar and cook for a further 10 mins until the onions are soft.
  2. Stir in the flour and mustard, and cook for 1 min. Add the stock and thyme sprigs and season well with salt and freshly ground black pepper. Bring to the boil, then reduce the heat to a simmer and cook for 30-40 mins.
  3. Lightly toast the slices of French bread and top with the cheese. Return to the grill for 1-2 mins until the cheese melts. Remove the thyme sprigs from the soup. Ladle the soup into deep bowls and top each with 2 cheese toasts. Serve immediately, garnished with thyme leaves.
Top Tip for making Red onion soup and cheese toasts

Swapping the Gruyère for half-fat Cheddar lowers the calories even more.The soup can be frozen for up to three months. Defrost at room temperature, then reheat gently for at least 10 mins until piping hot. Do not freeze the cheese toasts - these need to be made just before serving.


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