Start with the gnocchi. Cook the potatoes in boiling salted water until tender and the skins are starting to split, about 30–35 minutes. Drain well.

Meanwhile, to make the sugo, heat the oil in a medium saucepan over medium–low heat. Add the garlic and basil and cook until fragrant. Add the tomatoes, season and simmer for 25–30 minutes. Once cooked, adjust the seasoning if necessary and tip into a large baking dish.

Bring a large saucepan of salted water to the boil - it's important to have this ready to cook the gnocchi as soon as they're made. Preheat the oven to 180°C fan–forced (200° conventional).

Using a tea towel or gloves, peel the potatoes while still hot and pass through a potato ricer. Add a pinch of salt, the egg yolk and three–quarters of the flour and bring together into dough, adding a little of the remaining flour if needed.

Dust the bench with flour and roll the dough into logs about 2cm thick. Cut each log into 3–4cm pieces and place in a fine sieve to shake off any excess flour.

Working in batches, cook the gnocchi in the boiling water. Once they have risen to the surface, remove with a slotted spoon, briefly drain and add to the sugo in the baking dish. Repeat for the remaining gnocchi, making sure that the water comes back to the boil each time.

Gently mix the gnocchi through the sugo, sprinkle over the parmesan to taste, scatter over the buffalo mozzarella and bake for 10–12 minutes until the mozzarella has melted.