Wash the zucchini and cut into coarse oblong pieces.
Heat some olive oil in a large frying pan over medium heat. Peel and slice the garlic and onion and sauté briefly in the olive oil.
Add the spaghetti to the boiling salted water and cook according to package directions until al dente.
In the meantime, drain and dice the feta.
Add the zucchini pieces to the frying pan and sauté for 4-5 minutes. Then add one or two tablespoons of pasta water and some grated lemon zest. Squeeze the lemon and add the juice and the feta cubes.
Drain the finished pasta and then add it directly to the frying pan, season with salt and pepper and mix everything thoroughly.
Finally, arrange on deep plates, garnish with fresh parsley to taste and serve hot!Buon appetito!