1 large handful basil leaves, torn into small pieces
2 garlic cloves, crushed
1 large onion, chopped
3 x 400g tins chopped tomatoes
录 - 陆 tsp dried chilli flakes
2 tsp balsamic vinegar
salt and freshly ground black pepper
3 tbsp extra virgin olive oil
2 tsp sugar
grated Parmesan, to serve (optional)