How to Make It
Preheat the oven to 450° and place a large rimmed baking sheet in the oven to heat. Season the chicken generously on both sides with salt and pepper. Drizzle 2 tablespoons of the olive oil onto the hot baking sheet. Arrange the chicken in a single layer on the hot sheet and roast for about 5 minutes, until the chicken begins to brown.
In a medium bowl, toss the mushrooms and lemon slices with 2 tablespoons of the olive oil, then carefully scatter evenly around the chicken in the oven. Roast for about 30 minutes, until the mushrooms and lemon are browned and the chicken is cooked through.
Meanwhile, in a small bowl, mix the remaining 6 tablespoons of olive oil with the 1/2 cup of parsley, the vinegar and garlic. Season the sauce with salt.
Transfer the chicken, mushrooms and lemon slices to a platter. Drizzle with some of the sauce and garnish with lemon and parsley. Serve, passing the remaining sauce at the table.