1 tsp lemon juice
1 slice onion, ¼in/5mm thick
a few parsley stalks
4 heaped tbsp finely chopped fresh parsley
¾´Ç³ú/20²µ plain flour
1 bay leaf
salt and freshly milled black pepper
1 blade of mace
10 whole black peppercorns
1½´Ç³ú/40²µ butter
15fl oz/425ml milk
1 tbsp single cream