Heat the oil in a large frying pan over medium-high heat. Add the onion, carrot, celery and garlic. Cook, stirring, for 5 mins or until the onion softens. Add the mince and cook, stirring with a wooden spoon to break up lumps, for 5 mins or until mince changes colour.
Add the wine or stock to the mince mixture in the pan and bring to the boil. Add the tomato, tomato paste, bay leaves and mixed herbs and bring to the boil. Reduce heat to medium-low and cook, stirring occasionally, for 30 mins or until the sauce thickens. Remove and discard the bay leaves. Season.
Preheat oven to 200°C. Cook one-quarter of the gnocchi in a large saucepan of boiling water for 2-3 mins or until gnocchi rise to surface of the pan. Use a slotted spoon to transfer to a tray lined with baking paper. Repeat, in 3 batches, with remaining gnocchi.
Add gnocchi to the sauce in the pan. Gently toss to combine. Spoon into a baking dish and sprinkle with mozzarella. Bake for 20 mins or until the mozzarella melts and is golden brown. Divide among serving plates. Season.
Tip: SERVE WITH mixed salad leaves