Onion soup with GruyÃ¨re croÃ»tons

Fruit and vegetables

1kg/2lb 4oz onions, finely sliced

1.2 litres/2 pints stock (ideally beef but chicken or vegetable would also be fine)

50g/1Â¾oz butter

150g/5Â½oz GruyÃ¨re cheese, grated

1 baguette, cut into 1cm/Â½in slices

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