Place the stock in a pot and heat over medium low. You want the stock to be warm when adding it to the risotto so that the temperature change does not affect the rice.
6 cups vegetable stock
In a large pot, melt 3 tablespoons of the butter over medium heat. When melted, add the red onion. Cook until the onion is translucent but not yet browning, approximately 3-5 minutes.
6 Tablespoons unsalted butter, 2 Tablespoons red onion
Add the rice and stir. Continue cooking to slightly toast the rice until it is just starting to show a little brown color, approximately 3-5 minutes.
1 ½ cups arborio rice
Add the white wine to the pot. Cook until the rice is almost dry, where most of the wine has been absorbed.
1 cup white wine
Add one cup of stock to the rice. Stir continuously until most of the stock has been absorbed. Repeat this process one cup of stock at a time until the rice is cooked thoroughly. You want the rice to have just a little bit of bite left so that it is not completely mushy. Depending on your rice, you may need more or less stock for the right consistency so start tasting the rice after 4 cups.
While cooking the risotto, grate the zucchini. Heat a large skillet with 1 Tablespoon of oil. When hot, add the zucchini and corn. Sauté until the zucchini is just cooked through (not soggy), approximately 3 minutes. Set aside.If using fresh, raw corn, also cook it in this step along with the zucchini.
12 ounces zucchini
When your rice is cooked through, remove the pot from the heat. Add the rest of the butter, the Parmesan cheese, zucchini, and corn. It is important to do this before adding salt and pepper because the cheese is salty. Stir to combine.
¾ cup corn, 1 cup freshly grated Parmesan cheese
Taste the risotto and season with salt and pepper as desired. Serve immediately.
black pepper, salt
Notes
Use any white wine that you enjoy drinking. I advise staying away from sweet wines as it will make the risotto very sweet as well. Chardonnay or sauvignon blanc are the ones I tend to use.It may appear like a lot of zucchini, but it is a light flavor. Add more or less as desired. I like to use a full pound of zucchini. You can also chop the zucchini.To ensure a truly vegetarian dish, make sure your cheeses are vegetarian.