Start by cooking the pasta in a large pot of salted boiling water until al dente according to package instructions. Drain and set aside.
While the pasta cooks, heat 1 tablespoon of olive oil in a pan and sauté the zucchini and broccoli for 3 minutes.
Add the remaining oil, bell peppers, tomatoes, and garlic, and season with salt and pepper. Continue to sauté until the vegetables are just tender, but not overly soft.
Combine the cooked pasta and vegetables in a large bowl, add the sliced red onion, and pour over the vinaigrette. Toss to coat evenly.
If desired, sprinkle with Parmesan cheese before serving. Can be enjoyed immediately or stored in the fridge for later.