1. Coarsely grate the courgettes into a colander. Season with salt, toss and place the colander over a bowl for 30 minutes. When ready to cook, bring a large pan of salted water to the boil, add the spaghetti and cook for 8-10 minutes.
2. Meanwhile, squeeze the courgette to remove as much liquid as possible. Warm a frying pan over a medium heat. Add 2 tbsp olive oil. Tip in the lemon and pepper crust and toss for 5-6 minutes, until the crumbs are golden. Remove from the heat and keep warm.
3. Drain the pasta, reserving some of the cooking water. Return the pasta to the pan and add the courgette and shrimps. Toss, adding a little reserved cooking water and more olive oil, if liked, to create a sauce. Divide between 4 bowls, top with the crumbs and ground black pepper, and serve immediately.