1. Heat oven to 425 degrees. Cut 6 garlic cloves crosswise into very thin slices. Set aside in a small bowl. In another small bowl, set aside 12 cloves. Pick leaves from 3 or 4 sprigs oregano, and set aside in a small bowl. Set aside 3 sprigs oregano. Place remaining garlic cloves and oregano, onion, celery, and bay leaves in the bottom of a medium nonstick roasting pan.

2. With your finger, gently loosen the skin on the breast of the hens. Gently slide a few garlic slices and a few oregano leaves under the skin in a single layer. Place 4 garlic cloves, 1 sprig oregano, and 2 lemon wedges in the cavity of each hen; set aside remaining lemon wedges.

3. Tie each hen's legs together with kitchen twine. Tuck wings under breast; place hens in pan over the garlic mixture.

4. Add wine and 1/2 cup chicken stock to pan. Brush the skin with melted butter; transfer pan to oven.

5. Cook, basting occasionally and adding more chicken stock to pan if dry, until golden brown and internal temperature reaches 165 degrees when measured with a meat thermometer, 45 to 60 minutes. Remove hens from pan, and set aside on a board to rest 5 minutes before serving with reserved lemon wedges.