Peel and finely chop the onion. Clean and wash the celery and zucchini and also dice finely. Wash lemon hot, dry and peel or finely grate the peel in thin strips. Squeeze the lemon.
Heat the oil in a wide saucepan. Sauté the onion over medium heat until translucent. Fry celery and half of the lemon peel briefly. Add the rice and continue to fry for 1-2 minutes while stirring until the rice grains start to "crackle" and become glassy.
Add wine and let it evaporate at medium heat for a few seconds while stirring. Add lemon juice and hot stock until the rice is covered. Stir from time to time, adding broth from time to time. Add zucchini and bay leaf. Simmer rice open over low heat for 15-20 minutes, stirring continuously. Add stock until the rice is creamy.
Roast pine nuts in a pan without fat. Crumble the feta. Grate parmesan. Stir in the feta and half the parmesan. Season to taste with salt and pepper. Wash basil, shake dry, chop coarsely. Sprinkle the risotto with pine nuts, basil, remaining parmesan and lemon peel.