1. Place the zucchini in a bowl of cold or icy water and soak for 20 minutes (this will freshen and firm them). Drain, pat dry and cut into ¼-inch dice. Heat water until simmering.
2. Heat olive oil in a deep saucepan over medium heat. Add the onion, sauté until soft and translucent, about 10 minutes. Add the garlic and sauté for 2 minutes more, or until just starting to turn golden. Add the diced zucchini, season with salt and sauté until the zucchini softens and wilts slightly, about 10 minutes.
3. Add the rice and sauté until the edges become translucent, about 3 minutes (don’t let it burn). Add the wine and cook until evaporated, about 1 minute. Add a ladleful of the simmering liquid and cook, stirring constantly, until absorbed. Continue to add the liquid, one ladleful at a time, stirring continuously until it has almost completely evaporated (but the rice isn’t sticking) before adding more. Continue 18–20 minutes, until the rice is tender but still a little firm at the very center (al dente). It will continue to cook for at least 3 more minutes, so don’t overcook. If you run out of the hot liquid before the rice has finished cooking, use a little more boiling water.
4. Remove the rice from the heat and add the Parmesan, butter, salt and a generous amount of pepper. Stir vigorously with a wooden spoon for 1 minute. Garnish each with a spoonful of salsa di pomodoro, a sprinkle of torn basil leaves and a drizzle of your best extra-virgin olive oil. Pass more grated Parmesan at the table.