Juicy chicken breasts filled with sweet caramelized onions and melted cheese—a special dinner treat that feels gourmet yet cozy!
- 2 tbsp unsalted butter
- 4 tbsp extra virgin olive oil, divided
- 4 large white onions, thinly sliced
- 1 tsp sugar
- 2 tsp fresh thyme
- 1 tbsp balsamic vinegar
- 1 cup beef broth, divided
- 3 cloves garlic, minced
- 4 boneless, skinless chicken breasts
- 1½ cups Gruyere cheese, grated
- ½ cup Parmesan cheese, freshly grated
- Kosher salt and freshly ground black pepper, to taste
Preheat Oven:Preheat your oven to 400°F. Lightly grease a 9x13-inch baking dish with butter or nonstick cooking spray. Caramelize the Onions:Heat 2 tablespoons butter and 2 tablespoons olive oil in a large skillet over medium-high heat. Add sliced onions and cook, stirring occasionally, until they soften. Reduce heat to medium if onions start browning too quickly. Deepen the Flavor:Sprinkle onions with salt, sugar, and fresh thyme. Continue cooking, stirring every few minutes, until onions turn deeply golden and jammy—around 30 minutes or longer. If onions become dry, gradually add up to ½ cup beef broth to keep them moist. Finish the Onions:Once caramelized, add balsamic vinegar to the pan, scraping any browned bits from the bottom. Stir in minced garlic and cook for an additional minute until fragrant. Remove from heat and set aside. Prepare the Chicken:Carefully cut a lengthwise pocket into each chicken breast, without slicing all the way through. Fill each pocket generously with about 2 tablespoons caramelized onions and a mixture of Gruyere and Parmesan cheeses. Secure pockets with toothpicks. Assemble the Dish:Spread remaining caramelized onions evenly in the prepared baking dish and stir in the remaining ½ cup beef broth. Sear the Chicken:Heat the remaining 2 tablespoons olive oil in a clean skillet over medium-high heat. Season stuffed chicken breasts with salt and pepper. Sear chicken until golden brown on each side, about 4 minutes per side. (Chicken doesn't need to cook completely during this step.) Bake to Finish:Place seared chicken breasts on top of onions in the baking dish. Spoon some onions and juices over each breast, and sprinkle with remaining cheeses. Bake uncovered for 15-20 minutes, or until chicken is fully cooked and cheese is melted and bubbling. Serve and Enjoy:Remove toothpicks before serving. Enjoy this delicious, hearty dish hot from the oven!