Wash the zucchini, peel the potato and cut both in a small pieces.
In a pan, over low heat, heat up 2 tbsp of extra virgin olive oil with the peeled garlic. After few minutes add the zucchini, the potato and the oregano. Slowly, add the water and the vegetable bouillon cube. Cover the pan with a lid and cook over low heat for at least 20 minutes.
After that, blend the zucchini and the potato with an immersion blender.
Meantime, in a large pan heat the sausage with 1 tbsp of extra virgin olive oil, crushing it with a fork so that it crumbles.
Cook the Spaghetti alla Chitarra Filotea in plenty of salted boiling water for 3 minutes and set aside a little of cooking water.
Drain the egg pasta and toss it in the pan with the sausage. Add the zucchini velvet sauce and mix everything accurately.
If necessary, add some pasta cooking water in order to make the pasta more creamy.
Serve adding pepper to taste, parmesan cheese shavings on top and enjoy!