Parmesan Chicken With Balsamic Butter Sauce

Name: Parmesan Chicken With Balsamic Butter Sauce
Ingredients: One 3-pound chicken, cut into 8 pieces; 1/4 cup extra-virgin olive oil; 1/4 cup freshly grated Parmesan cheese; 2 tablespoons minced oregano; 2 garlic cloves, minced; Salt and freshly ground pepper; 1 cup chicken stock or canned low-sodium broth; 1/2 cup balsamic vinegar; 2 tablespoons cold unsalted butter