Cut bread into rhombs. Melt the fat in a frying pan, fry the bread in it until golden brown while turning, remove from the pan and set aside. Peel ginger and grate finely. Bring beer, ginger and caraway seeds to the boil.
In the meantime, whisk the egg yolk and starch. Wash the chives, dab dry and cut into fine rolls. Stir the whisked egg yolk into the boiling beer. Melt the currant jelly in it.
Season the soup with salt and pepper and arrange it in a deep plate, sprinkled with bread and chives.