Peel onion and garlic and chop them finely.
Cut zucchini into thin slices or half slices.
Put some olive oil in a large, deep, coated frying pan and fry the onion and garlic until translucent.
Add risotto rice and zucchini and stir-fry for about 3 minutes.
Deglaze the zucchini and rice mixture with white wine and cook, stirring, until the wine is almost evaporated, about 2 minutes.
Add warm vegetable broth, stir, bring to a boil and simmer, stirring, until rice is cooked through, about 20 minutes.
When the vegetable broth has almost completely evaporated but the rice is not yet cooked, keep adding vegetable broth in batches.
Just before the risotto is done, season it with salt and pepper.
Before serving, divide the zucchini risotto among plates and sprinkle with yeast flakes and fresh basil.