Cook the pasta according to the package directions. Reserve 1/2 cup of the pasta water.
In a large skillet, sauté the onion, carrot, and broccoli for 5 minutes, until starting to soften.
Add the pepper, squash, zucchini, garlic, and tomatoes. Cook another 5-7 minutes, until all the vegetables are soft.
Add the cooked pasta to the veggies and stir in the Italian dressing, lemon juice, and 1/4 cup of the pasta water. Stir to coat the vegetables, adding the remaining 1/4 cup of water as necessary to create a creamy sauce.
Season with salt and pepper and garnish with fresh parsley and grated parmesan.