Baked American-style meatballs in smoky tomato sauce

Method

1. Heat 3 tbsp of the olive oil in a large, deep frying pan, add the onions, garlic and oregano, cover and cook over a low-medium heat for 10 minutes or until soft and lightly browned. Turn off the heat, scoop half the mixture into a large mixing bowl and set aside to cool.
2. Return the frying pan to a medium heat, add the tomato purée and balsamic vinegar, then stir well. Add the chopped tomatoes, chilli paste or Tabasco, sugar, thyme leaves, beef stock and a little seasoning, then bring to a gentle simmer.
3. Put the bacon in a food processor and pulse briefly until finely chopped. Add the bacon to the cooled onions with the beef mince, breadcrumbs, fresh oregano, egg, ½ tsp salt and some black pepper. Mix using your hands, then roll into balls about the size of a golf ball (it will help if you oil your hands lightly before rolling).
4. Heat the remaining 2 tbsp oil in another large frying pan and fry the meatballs in 2 batches until brown all over. Transfer to the simmering sauce using a slotted spoon, stir in and leave to simmer uncovered for 20 minutes or until the meatballs are cooked through and the sauce has reduced and thickened. Leave to cool, then spoon into a freezer proof container. Seal and freeze until required (see make ahead).
5. When ready to serve, remove the meatballs from the freezer and defrost overnight in the fridge. Heat the oven to 240°C/fan220°C/gas 9. Spoon the meatballs and sauce into a shallow 2.5 litre baking dish, making sure the meatballs are well covered. Scatter over the grated cheeses, then bake for about 15 minutes or until golden and bubbling. Remove, scatter with extra chopped fresh oregano and serve with fresh crusty bread or hot garlic bread.