To prepare a spaghetti with roasted zucchini and olives, you will first need to prepare the pasta. Cut the zucchini in half lengthwise, and then cut each half into 1/4-inch slices. Toss the slices with the olive oil, salt and pepper. Place the pieces of zucchini into the boiling water and cook until they are tender, about 5 minutes. Drain the spaghetti and add it to the pot. Add the remaining ingredients and stir to combine. Cook the mixture over medium heat, stirring occasionally, until the noodles are al dente. Serve immediately.