Clean and wash the radicchio and lamb's lettuce and drain well. Pluck the radicchio into bite-sized pieces. In the meantime, cut bread into large cubes. Heat the fat in a pan and fry the bread cubes in it until golden brown.
Peel onions and cut them into fine rings. Chop the cheese roughly. Mix apple juice and vinegar. Season with salt, sugar and coloured pepper, fold in oil. Mix salad ingredients and vinaigrette and sprinkle with hazelnut leaves and croutons.
Arrange on plates and garnish with apple slices as desired and serve.