Ingredients

• 4 chicken breast halves with skin and bones (about 2 1/2 pounds total)
• 1/4 pound chilled Gorgonzola dolce, sliced
• 1 tablespoon vegetable oil
• 1/3 cup water
• 2 1/2 tablespoons balsamic vinegar

Instructions

1. Preheat oven to 425°F with rack in middle.
2. Pat chicken dry, then cut a deep 3-inch-long pocket horizontally in long curved side of each chicken breast half. Fill each pocket with one quarter of cheese. Season chicken all over with 1 teaspoon salt and 1/2 teaspoon pepper.
3. Heat oil in an ovenproof 12-inch heavy skillet over medium-high heat until it shimmers. Place chicken, skin side down, in skillet and cook, undisturbed, until golden brown, about 4 minutes. Turn breasts over, then place skillet in oven and bake until just cooked through, 20 to 25 minutes. Transfer chicken to a platter.
4. Return skillet to burner (handle will be very hot) and add water and vinegar. Boil, stirring and scraping up any brown bits and melted cheese, until sauce thickens slightly, about 3 minutes. Strain through a fine-mesh sieve into a heatproof measuring cup, then skim off excess fat. Season with salt and pepper. Serve chicken with sauce.