Toast slices of toast in a toaster and brush with butter. Wash the apple, quarter it and remove the core. Cut quarter into slices. Spread the slices on the toasts, crumble the cheese over them.
Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for approx. 4 minutes. Wash and clean the radicchio and cut into fine strips. Cut the cress from the bed. Spread the radicchio on the toasts.
Sprinkle with coarse pepper and cress.