Combine the plum tomatoes and the prepared marinara sauce in a saucepan and place over medium heat. When almost to the boiling point reduce heat, cover and simmer for 20 minutes. Remove the cover, stir in the basil and continue to simmer about 15 to 20 additional minutes, until ready to serve. Wash vegetables. Cut squash in half lengthwise and then into thin slices. Core peppers and cut into 1/2" cubes. (Other fresh vegetables may be substituted.) Prepare the pasta according to package directions. While pasta is cooking heat olive oil in a large skillet. Add the vegetables and stir fry until tender crisp. Drain pasta and combine with the cooked vegetables. Serve the vegetable pasta mixture with the marinara sauce and Parmesan cheese. Makes 8 servings.