Spray inside of pot with non stick spray. Add the onion, red bell pepper, zucchini, beans, and mushrooms. In a mixing bowl, stir together the diced tomatoes, tomato paste, chicken broth, and seasonings.
Add this tomato mixture to the slow cooker and gently fold in to combine with the vegetables. Cover the slow cooker and cook on low for 5 to 6 hours.
Gently stir in the cooked pasta. Sprinkle cheese over the top and cover until the cheese has melted and noodles are as tender as desired (about 30 min). Serve garnished with grated parmesan