Gnocchi Sorrentina with Mozzarella

Heat a generous amount of olive oil in a medium-sized saucepan over an intermediate heat setting; cook the onion until it becomes soft and loses its initial firmness, approximately 5 minutes. Introduce passata and a pinch of salt into the mixture; continue to cook over a very low heat setting while you prepare your gnocchi.

Prepare a large container of water by adding a moderate amount of salt; bring the water to a rolling boil. Cook your gnocchi in the boiling water until they rise to the surface, typically taking 2 to 4 minutes. Drain the cooked gnocchi.

Position an oven rack about 6 inches away from the heat source and preheat your oven's broiler to a high temperature.

Pour 1 ladle of tomato sauce into the bottom of a baking dish. Add your cooked gnocchi, remaining tomato sauce, and grated Parmesan cheese; mix everything together thoroughly. Distribute cubes of mozzarella cheese evenly across the top surface.

Place your baking dish in the oven and expose it to high heat until the mozzarella cheese is melted and the sauce has slightly diminished, taking 5 to 10 minutes. Remove your dish from the oven and garnish it with fresh basil leaves before serving.