Place potatoes and chicken in a casserole dish. Drizzle with the Tuscan Herb Olive Oil and lemon juice. Sprinkle with rosemary, garlic, salt, and pepper. Cover and refrigerate for at least 30 minutes.
Preheat oven to 400 degrees. Sprinkle green onions over chicken.
Bake, covered, for 30 minutes. Remove, add olives and mushrooms. Return to oven and bake for 30 minutes.