Heat the oil in a large non-stick frying pan with a lid, then tip in the onion, carrots, celery, garlic and fennel, and stir well. Cover the pan and cook over a medium heat for 8 mins, stirring every now and then. Pour in the passata and season well with salt and pepper. Cover and leave to simmer for 20 mins.

Meanwhile, tip the mince into a large bowl. Add the oats, fennel seeds and leaves, the garlic and plenty of black pepper, and mix in with your hands. Lightly shape into 25 meatballs about the size of a walnut. Spray or rub a non-stick pan with a little oil and gently cook the meatballs until they take on a little colour. Give the sauce a stir, then add the meatballs and parsley. Cover and cook for 10 mins until they are cooked through and the veg in the sauce is tender. Serve with broccoli and baby potatoes in their skins, or pasta and salad.