While the pasta cooks, heat the olive oil in a large skillet over medium heat. Add the corn, chopped onion, and minced garlic. Sauté for about 5 minutes, until the onions soften and the corn is tender.
Return the blended corn sauce to the skillet with the remaining corn and vegetables. Add the tomatoes (if using) and drained pasta, along with 1/4 cup of the reserved pasta water.