Cook the gnocchi in a large saucepan of lightly salted boiling water for 2–3 minutes, or according to packet instructions, until the gnocchi is plump and rises to the surface.
Meanwhile, heat the butter in a large frying pan over a moderate heat. When the butter starts to foam, stir in the sage leaves and pine nuts and cook for 1–2 minutes, until the sage is crispy and the pine nuts are golden. Add the gnocchi and toss to combine.
Divide between 4 bowls and serve sprinkled with the Parmesan and plenty of freshly ground black pepper. Serve with a crisp green salad.