I always like a pasta dish that does NOT use tomatoes!
I put water on to boil for the pasta, slice half the courgettes finely with the mandolin and finely chop half an onion. I whizz the other half in the Magimix and create a paste with a ladle of cooking water from the pasta, a good spoon of butter and fresh basil. In a non-stick frying pan, I sauté the onion and courgette slices in olive oil and add the courgette paste after a few minutes. I add salt and pepper. I cook a few minutes more, add the cooked, drained pasta with a little cooking water. Parmesan and a final grating of pepper.
PS I didn’t actually do it this way in the photo, but this is the way you’re supposed to!