Preheat the oven to 220°C, fan 200°C, gas 7. Make the meatballs by mixing the turkey mince, onion, carrot and nutmeg thoroughly. Shape into around 30 bite-size meatballs.
Lightly grease a large roasting tin with the oil and add the meatballs. Sprinkle over the celery and bake for 15 minutes, shaking halfway through. Pour in the tomatoes and 100ml water and stir well. Place back in the oven for 10 minutes, while you cook the pasta.
Cook the rigatoni in boiling water for 10 minutes and drain. Divide the pasta between plates and spoon over the meatballs and sauce – allow 10-12 for each adult and divide the rest between the children.