Wash and drain the spinach.

Tip the spinach into a large pan over a medium heat and cook until the leaves are wilted and tender. Drain and leave until cool enough to handle, then squeeze the spinach between your hands to remove as much water as possible and roughly chop.

Melt the butter in a sauté pan, add a quarter of the chopped onion and cook over a medium heat until tender but not coloured.

Add the chopped spinach and cook for a further 2 minutes.

Blend in the food processor or with a stick blender.

Tip into a bowl, season with freshly grated nutmeg, salt and black pepper and leave to cool.

Add the ricotta, Parmesan, plain flour and egg yolks to the mixture and mix until smooth.

Cover and chill the mixture for a couple of hours to firm up.

Meanwhile prepare the tomato sauce. Heat the olive oil in a saucepan over a medium heat, add the remaining onion and cook until soft but not coloured. Add the crushed garlic and cook for a further minute. Add the canned tomatoes, caster sugar and season well with salt and freshly ground black pepper. Bring to the boil and simmer over a medium heat for about 7 minutes until slightly thickened. Add the chopped basil.

Lightly dust the work surface with a little plain flour and roll the spinach mixture into a log about 3cm in diameter.

Cut the log into 3cm pillows or gnocchi and lay on a baking tray that has been lightly dusted with plain flour. Bring a large pan of salted water to the boil.

Add the gnocchi and cook for about 3 minutes until tender and the gnocchi float to the surface of the water. Drain the gnocchi and serve in bowls with the tomato sauce, scattered with grated Parmesan and drizzle with extra virgin olive oil.