Step 1: Prepare the Chicken
- Preheat the Oven: Preheat your oven to 375°F (190°C).
- Season the Chicken: Pat the chicken breasts dry with paper towels. Season both sides with salt, black pepper, garlic powder, onion powder, and thyme.
- Sear the Chicken: In a large oven-safe skillet or a Dutch oven, heat the olive oil over medium-high heat. Add the seasoned chicken breasts and sear them for about 3-4 minutes on each side, until golden brown. You don’t need to cook them all the way through, as they will finish cooking in the oven. Remove the chicken from the skillet and set it aside.
Step 2: Caramelize the Onions
- Cook the Onions: In the same skillet, add the butter and the sliced onions. Cook over medium heat, stirring frequently, for about 10-15 minutes, or until the onions are soft and starting to caramelize.
- Add Sugar: Sprinkle in the sugar and continue to cook for an additional 5-10 minutes, until the onions are deep golden brown. If they begin to stick to the bottom of the skillet, add a splash of beef broth to deglaze the pan.
Step 3: Build the Casserole
- Add Broth and Soup: Pour in the beef broth, soy sauce, balsamic vinegar (if using), and the can of French onion soup. Stir to combine, scraping up any browned bits from the bottom of the pan.
- Return Chicken to the Skillet: Place the seared chicken breasts back into the skillet, spooning some of the onion mixture over the top. Ensure the chicken is mostly submerged in the sauce.
Step 4: Bake the Casserole
- Add Cheese: Sprinkle the shredded Gruyère cheese evenly over the chicken and onion mixture. If you like extra crunch, add French-fried onions on top of the cheese.
- Bake: Transfer the skillet to the preheated oven and bake for 25-30 minutes, or until the chicken is cooked through (internal temperature should reach 165°F or 74°C) and the cheese is bubbly and golden brown.
Step 5: Serve
- Garnish: Remove the casserole from the oven and let it rest for a few minutes. Garnish with freshly chopped parsley before serving.
- Pairing Suggestions: Serve this delicious casserole over rice, mashed potatoes, or alongside a green salad for a complete meal.
Tips for Success
- Cooking Chicken: Ensure the chicken is seared properly for added flavor and texture. Avoid overcrowding the pan to maintain high heat for a good sear.
- Onion Variations: You can also mix in shallots or caramelized mushrooms for additional flavor.
- Leftovers: Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven or microwave.
Conclusion
This Chicken with French Onion Flavor Baked in a Bubbly Casserole is the perfect dish for a cozy family dinner or gathering with friends. The combination of tender chicken, sweet caramelized onions, and gooey melted cheese makes for a hearty and satisfying meal that will keep everyone coming back for more. Enjoy!