Place the potatoes, skin-on, in a large pan and cover with cold water. Place over a medium heat and bring to the boil. Cook the potatoes until tender all the way through. Drain, peel and, while they are still hot, pass through a potato ricer into a bowl

Mix the potato mash with the tomato paste, garlic, Parmesan, parsley and a pinch of salt. Cover with a towel and leave to cool

Next, make the fresh pasta. Place the flour on a work surface, make a well in the middle and crack the eggs in its centre. Add the olive oil and a tablespoon of water. Beat the eggs, oil and water with a fork, incorporating the flour a little at the time, until you see some lumps of dough coming together. Carry on with your hands, kneading until you have a smooth, elastic ball of dough. Flatten the dough slightly, wrap it in cling film and leave it to rest for 30 minutes

Next, divide the dough into 3 pieces and roll them out using a pasta machine – I normally stop at to the second-to-last setting. Arrange the sheets of pasta on a floured work surface. Using a piping bag or a teaspoon, create heaps of potato filling onto the laid out pasta sheets, leaving about 3cm in between them. Fold the sheet of pasta onto itself to form small pockets. Press down the pasta in between heaps of filling to remove any air bubbles. Then, using a pasta wheel, cut out the tortelli

Bring a large pot of salted water to a rolling boil. Add the tortelli and cook until they start to float. Drain them with a slotted spoon and transfer to a saucepan. Toss with melted butter and sage or with a meat ragù

Serve right away with a dusting of grated Parmesan