25 g (1 oz) grated Parmesan cheese, plus extra to serve
1 rosemary sprig, finely chopped
1 garlic clove, crushed
2 tablespoons olive oil
500 ml (17 fl oz) ready-made fresh tomato sauce
600 g (1 lb 3 1/2 oz) spaghetti
salt and pepper
Put the mushrooms in a small pan, cover with the measurement boiling water and simmer for 2 minutes until soft. Drain, reserving the liquid.
Meanwhile, put the breadcrumbs in a small bowl, pour over the milk and leave for 1-2 minutes until absorbed, then mix together with the beef, egg, Parmesan, rosemary and garlic. Finely chop the porcini and stir into the mixture. Season to taste. Lightly wet your hands and form the mixture into meatballs about the size of a walnut.
Heat the oil in a large frying pan, add the meatballs and cook for 5–7 minutes, turning occasionally, until golden all over. Strain the mushroom soaking liquid, discarding any grit, and add to the pan with the tomato sauce. Leave to simmer for 15 minutes or until the meatballs are cooked through.
Meanwhile, cook the spaghetti according to the pack instructions. Drain, reserving a little of the cooking water, and return to the pan. Add the meatballs to the pan, together with some of the cooking water to loosen if needed. Transfer to serving bowls and scatter with Parmesan shavings.