Take a little of the milk, mix the proteid food and the cornflour to a smooth paste. Put the rest of the milk into the inner pan of the double-pan hot-air cooker (the outer pan, of course, to be filled with boiling water), and bring almost to the boil. Now add the mixed proteid food and the cornflour, and bring to the boil.
Add the raspberry jam or red-currant jelly, and stir all the time until quite thick. Pour the mixture into a mould which has previously been rinsed in cold water. Let the blancmange get cold, and turn into a glass dish.