1. Bake the potatoes whole in the oven for 45-50 minutes (skin on), until they are soft inside. Pass the potatoes through a potato ricer or a sieve, into a large bowl. Add the flour, egg, Parmesan, salt and pepper. Mix together until a dough forms.

2. While the dough is still warm, shape it into balls using your hand (around the size of a 20 cent coin). When rolled into a ball, press your thumb into the middle and then, using a fork, roll the ball to get an oval shape with the fork. Place on a greaseproof sheet dusted with flour.

3. Bring a large pot of salted water to a boil. Add the gnocchi to the water and cook for three minutes (until the gnocchi float to the surface). Remove with a slotted spoon and place into ice-cold water.

4. In a wide-bottomed pan, melt the butter over medium heat. Add the hazelnuts and minced garlic and cook for two minutes. Add the chopped sage leaves and cook for another minute. Add the gnocchi and cook until golden brown. Transfer to a bowl and garnish with more parmesan, the sage, and some cracked black pepper.