1-First Step: Position the oven racks in the upper and lower thirds if using two baking sheets, or in the center if using one. Preheat the oven to 400 degrees Fahrenheit.

2-Second Step: Generously coat 2 large, rimmed baking sheets with non-stick spray.

3-Third Step: Place the vegetables in a large bowl or directly on the baking sheets.

4-Fourth Step: Add the olive oil and mustard, then sprinkle with the Italian seasoning, salt, garlic powder, and black pepper. Toss everything together to ensure even coating, paying special attention to the broccoli florets.

5-Fifth Step: Divide the vegetables evenly between the baking sheets, spreading them into a single layer.

6-Sixth Step: Roast for 25 to 35 minutes at 400 degrees F, or if using convection, roast at 375 degrees F for 20 to 25 minutes.

7-Seventh Step: Halfway through cooking, toss the vegetables, rotate the pans 180 degrees, and switch their positions between the racks.

8-Eighth Step: The vegetables are done when they are brown and crispy on the edges and tender inside. Sprinkle with the Parmesan cheese and serve hot or at room temperature, adding extra salt and pepper if desired.