Heat the oil in a large frying pan over a
medium heat. Add the onion and cook for
about 10 mins until softened and starting
to go golden brown. Add the garlic and
cook for 5 mins more.
Add the courgettes and cook for
about 5 mins until starting to soften. Tip
in the tomatoes and give everything a
good stir. Simmer for 35-40 mins or until
tomatoes are reduced and courgettes
soft, then stir in the basil and Parmesan.