Spinach and Parmesan meatballs

Method

1. Heat the olive oil in a large saucepan, add the carrot, celery, garlic and onion and cook gently for about 4-5 minutes, until beginning to soften. Stir in the tomatoes, rinse out 1 of the cans with 100ml water and add to the pan. Season to taste. Bring to a gentle simmer, then cover the pan and cook for 15 minutes.
2. Meanwhile, put the spinach in a large colander and pour over boiling water to wilt. Cool, then squeeze out the excess water and finely chop.
3. Put the minced beef in a large bowl, add the spinach, breadcrumbs, Parmesan, chilli flakes, parsley, egg and some seasoning. Mix together with your hands until completely combined. It should be a firm, moist mixture but not sticky.
4. Roll the mixture into small balls, the size of a walnut – you should have about 30 – and drop into the tomato sauce. Shake them down into the sauce (stirring them while they are soft will break them apart) and cook for 35-40 minutes, until the meatballs are cooked through and the sauce is reduced and thickened.
5. Cool completely and freeze (see tip) or serve with linguine, cooked according to the pack instructions, and extra grated cheese