Wash the parsley, dry it and chop it finely. Trim the courgettes, rinse them and slice them lengthways in 4 and then slice them again in small segments. Cook the pasta in a saucepan with plenty of boiling salted water.Peel the clove of garlic and fry it until soft in a saucepan with 2 tbsp of oil. Add the courgettes, stir well, season with a pinch of salt, let them soften over a low heat for 3 minutes; Dilute the tomato concentrate in half a ladle of water, add it to the courgettes, cover and simmer for 3 minutes or until cooked. Fold in the leftover oil and complete with the chopped parsley.Drain the pasta, sprinkle it with parmesan, add the courgettes, stir well and serve immediately.