Heat the stock in a small pot over medium-low heat. I usually use the burner right behind the one I use for the skillet; you will want the pan of stock close to your skillet later on.

Heat a high-sided large skillet over medium-low heat. Melt the butter and olive oil together.

Add the scallions and cook, stirring, for two minutes until soft. Do not brown.

Add the zucchini, season with a little salt, and stir until they become soft, about 2 minutes.

Pushing the vegetables to the edges of the pan to create a space in the center, increase the heat and add the rice into the center of the pan. Stir, just the rice, until it is coated with the olive oil and begins to cook.

Using a fine grater, grate the garlic over the rice and stir the vegetables and rice together. Now create an open ring around the outer edge of the pan, leaving about a 1-inch space. Fill the space with the peas. Carefully stir the peas, keeping them in their ring to coat them with the oil. Sprinkle all with a small amount of salt.

Ladle one cup of broth over the rice in the center. Stir constantly, just the rice, until the liquid is absorbed. Add another ladle of broth to the rice portion of the pan; stirring constantly and keeping the peas at the outer edge. Repeat this process one more time for a total of three times. When the liquid is absorbed, the rice will not be cooked through, but it will be releasing it's starch and becoming creamy. This part of the process should take about 18 to 20 minutes.

Add the remaining broth, this time covering all of the ingredients. Now the peas will float. Shake and swirl the pan, allowing the ingredients to combine without stirring. Cook for an additional 8 minutes, until the rice is al-dente. Turn off the heat and stir in the butter. Taste and add more salt, if necessary.

Serve in a bowl topped with freshly grated Parmesan and black pepper.