Preheat oven to 400 degrees Fahrenheit. Line two baking sheets with Gefen Parchment Paper and spray with nonstick cooking spray.
Place the sweet potato and eggplant pieces on one baking sheet.
Place the mushroom and onion slices on the other baking sheet.
Spray vegetables with nonstick cooking spray and sprinkle with salt and Italian seasoning.
Roast mushrooms and onions for 20 minutes. Roast sweet potato and eggplant for 30 minutes.
Meanwhile, prepare the dressing: Mix all dressing ingredients to combine.
In a large bowl, toss the lettuce with the roasted vegetables. Add the dressing and toss again. Sprinkle with Parmesan cheese and serve.