Adapted from the Vegetarian Bible, p. 94
Heat 2 Tbsp of oil in a large skillet over high heat. When very hot, but not smoking, add the squash and bell pepper and stir-fry for 3 minutes, until lightly golden. Stir in the garlic and cook for about 30 seconds longer. Transfer to a plate and set aside.
Heat 2 more Tbsp of oil in a large heavy pan over medium heat. Add the onion and cook, stirring occasionally, for about 2 minutes, until soft. Add the rice and cook, stirring frequently, for about 2 minutes, until the rice is translucent and well coated with olive oil.
Pour in the vermouth; it will bubble and steam rapidly and evaporate almost immediately. Add a ladleful (about ½ cup) of the simmering stock and cook, stirring constantly, until the stock is completely absorbed.
Continue adding the stock, about half a ladleful at a time, letting each addition be absorbed before adding the next. This should take 20-25 minutes. The risotto should have a creamy consistency and the rice should be tender, but still firm to the bite.
Stir in the zucchini mixture with any juices, and the butter, basil, and grated parmesan. Drizzle with a little oil and garnish with basil. Serve hot. Tomato would be a great addition on top as well.