Heat the oil in a large oven-proof skillet. Fry your onion until translucent then add your sausagemeat. Break up into pieces and fry for 10 minutes or until nicely crisp. Add rosemary, chilli and garlic. Fry for a few more minutes.
Mix together the sugar, tomato puree and balsamic vinegar. Add to the skillet and fry to remove raw flavour.
Add passata, stir through and cook down for 10 minutes. Add the dried pasta and the water and cook for a further 10 minutes, stirring occasionally.
Top with the sliced mozzarella and parmesan then bake at 200°C for 20 minutes.