Preheat oven to 375 degrees.
Lightly oil a baking sheet or coat with nonstick spray.
Place mushrooms in a single layer onto the prepared baking sheet.
Add olive oil, lemon juice, lemon zest, garlic, thyme and Parmesan; season with salt and pepper to taste. Gently toss to combine.
Place in oven and bake for 12-15 minutes, or until browned and tender, tossing occasionally. Serve immediately.