In a small bowl, combine minced garlic and olive oil, allowing to infuse for 15 minutes. Cut the potatoes lengthwise into wedges. Place chicken into a baking pan with potatoes around chicken. Sprinkle with oregano, thyme and rosemary, salt and pepper. Add garlic-oil and wine.
Bake 20 minutes, turn chicken, bake another 20 minutes. Add cognac. Bake another 20 minutes, or until chicken juices run clear and the potatoes are tender.
Drizzle the pan juices over the chicken and potatoes on a platter.