How to Make It
Preheat the oven to 475°. Quarter the eggplant, zucchini and yellow squash lengthwise, then trim off the central portion with the seeds. Cut the vegetables into 1/2-inch dice. In a large bowl, toss the vegetables with 1/2 cup of the olive oil and the garlic. Season with salt and pepper. Spread the vegetables on 2 rimmed baking sheets and roast for 25 to 30 minutes, stirring twice, until tender.
Heat the remaining 2 tablespoons of olive oil in a large saucepan. Add the onion and saffron and cook over moderate heat, stirring, until softened, about 7 minutes. Add the sun-dried tomatoes and cook for 2 minutes longer. Stir in the stock and bring to a boil; simmer for 3 minutes. Season with 1 1/2 teaspoons of salt and 1/4 teaspoon of pepper. Stir in the couscous, cover and remove from the heat. Let stand for 5 minutes. Stir in the vegetables and basil and serve.