Bring a large pot of water to the boil. Add the pasta and cook 'al dente.
Meanwhile, grate the courgettes and set aside.
In a large frying pan, heat plenty of olive oil and add the anchovies, crushed garlic and sea salt. Fry for about 3 minutes, stirring continuously until the anchovies start to soften.
Sprinkle in the chilli flakes and freshly ground pepper, followed by the grated courgettes and a dash more olive oil. Stir for a further 2 minutes.
When the pasta is cooked (it should take 10 minutes), drain well and add to the sauce.
To serve, toss the pasta through the sauce and spoon onto plates. Grate fresh parmesan over the top and finish with freshly ground pepper.