Warm 4 cups of chicken or vegetable broth in a saucepan over low heat. Keep it at a low simmer.

In a large skillet or wide saucepan, heat 2 tablespoons of olive oil over medium heat. Add 1 small diced onion and sauté until soft and translucent, about 5 minutes. Stir in 2 minced garlic cloves and cook for 1 minute until fragrant.

Add 1 cup of Arborio rice to the skillet and stir well to coat it in the oil. Toast for 1–2 minutes, stirring constantly, until the rice is slightly translucent around the edges.

Pour in 1/2 cup of dry white wine and cook, stirring, until the wine is mostly absorbed.

Begin adding the warm broth, one ladleful (about 1/2 cup) at a time, stirring frequently. Wait until the liquid is mostly absorbed before adding the next ladleful. Repeat this process for about 20 minutes, or until the rice is tender but still has a slight bite.

Stir in the grated zucchini and cook for another 3–5 minutes, adding broth as needed, until the zucchini softens and integrates into the risotto.

Turn off the heat and stir in 1/4 cup grated Parmesan cheese, 1 tablespoon butter, and 1 teaspoon lemon zest. Mix until creamy and well combined. Adjust seasoning with salt and black pepper to taste.

Serve immediately, garnished with fresh parsley or basil and extra Parmesan cheese.