Peel the potatoes and cook in salted water for approx. 20 minutes and drain.
Place the potatoes on a baking sheet lined with baking paper with a little space in between. With a potato masher, gently press the potatoes in until they burst, but do not pound them to a pulp. Drizzle with olive oil, season with salt, pepper and sprinkle with parmesan.
Bake crispy in the oven at 160 ° C (180 ° C electric stove) for 20 minutes.
Variation:
Use less olive oil and pour browned butter over it before serving.