Bring a large pot of salted water to the boil and cook the pasta according to the instructions on the package. When cooked, rinse the pasta under cold running water until warm but not completely chilled, set aside to drain.
Place the broccoli florets, bell peppers and mushrooms in that prepared pan. Drizzle with the olive oil and then sprinkle with salt and pepper. Place the pan in the oven and let the veggies roast for about 20 minutes, or until they become soft and start to darken. Toss once, halfway through cooking.
Combine all the ingredients for the dressing in a small bowl or measuring cup and mix with a whisk until well combined and slightly emulsified.
Put the cooked pasta in a large mixing bowl, top with the roasted veggies, grated Parmesan cheese, chopped parsley and dressing. Toss until well combined.
You can serve the salad now, or leave it to rest for a couple of hours to allow flavors to meld.
This salad will keep for up to a week if kept refrigerated in an airtight container.