Preheat oven to 400 degrees F. Line a baking sheet with parchment paper or nonstick foil and set aside.
Whisk together the garlic, olive oil, vinegar, sugar, mustard and parsley in a medium bowl. Add the mushrooms and toss to coat. Season with salt and pepper then place on the prepared baking sheet.
Bake for 15-20 minutes or until the mushrooms are golden and tender, tossing once during cooking.
Recipe by Lemon & Mocha at http://www.lemonandmocha.com/2014/12/12/balsamic-roasted-mushrooms/