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Melt the butter in a saucepan and add the sliced onion. Fry gently until soft but not brown, then add the Stilton. Stir with a wooden spoon until the cheese melts to form smooth cream. Add the flour and cook for further 5 min, stirring continuously. Add the stock, bay leaf and seasoning and bring to the boil, stirring. Simmer for 20 min. Remove the bay leaf, taste and check seasoning, then add the cream and serve at once.
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How many minutes do we simmer the stock?