In a large sauté pan, heat the olive oil over medium heat. Add the onion and cook for 4-5 minutes, until soft. Add the zucchini and cook for another 5 minutes, stirring occasionally. Season with sea salt. Add the rice, stir, and cook for 3 to 4 minutes until the rice is opaque.
Add the wine and a ladleful of hot stock. Cook, stirring, until the liquid is absorbed. Continue stirring and adding the stock one ladle at a time, waiting until the liquid is absorbed each time before adding more liquid. Add liquid until the rice is tender but al dente and the risotto looks creamy, about 18-20 minutes.
Remove the pan from the heat. Stir in the butter and the parmigiano reggiano. Taste. Season with sea salt as necessary. Divide the risotto among four bowls. Drizzle with extra virgin olive oil, sprinkle with basil, and finish with black pepper. Serve with parmigiano reggiano.