For the gnocchi, chop the potatoes into even-sized pieces, and then cook them until tender. Mash the potatoes or pass them through a sieve. Add 2/3 of the Parmesan cheese, egg yolk, and season well with salt and freshly ground black pepper. Add the flour and quickly work it into the potato till you have a nice, smooth dough. If the dough is slightly sticky, add in a little more flour. Cut the dough into three or four pieces and roll each into a long tubular shape, about the thickness of your finger, and cut off pieces 2.5cm/1in long. Roll each one into an oblong. As you go, keep the gnocchi on a tray, sprinkled in a little flour (semolina or rice flour are best as they will not be absorbed into the dough). To cook the gnocchi, drop batches into a large saucepan of boiling water, taking care not to over crowd the pan or the gnocchi will stick. The gnocchi are done when they float to the top. Remove the cooked gnocchi with a slotted spoon and toss in a little olive oil. For the sauce, melt the butter in a pan with the remaining olive oil and fry the sage, garlic and walnuts for 1-2 minutes. Gently place in the cooked gnocchi and coat in the pan juices. Share out the gnocchi and sauce between 2 large serving plates, and sprinkle over the remaining cheese.

Suggested accompanying wine: DELICATA Grand Vin de Hauteville Oak aged Chardonnay D.O.K. Malta