Melt the butter in a saucepan, then stir in the flour, curry powder and salt.
Cook for 2 minutes, then gradually stir in the milk to make a very thick sauce. Cook this for 5 minutes, stirring all the time, and then take the pan off the heat and add the beaten egg, tomato purée , Worcestershire sauce and lemon juice. Now add the hard-boiled eggs, stir to mix them in and season with salt.
Next transfer the mixture to a bowl, cover and chill until the mixture becomes firm.
Then before cooking form the mixture into 4 little round cakes, about 2cm thick, and dip them first in the seasoned flour, then in the beaten egg and finally in the breadcrumbs. Now shallow-fry them in 5mm of hot oil till golden brown and drain on kitchen paper before serving.