Ingredients

For the chicken:

• 4 boneless, skinless chicken breasts (6-8 oz each)

• 2 tbsp olive oil

• Salt and freshly ground black pepper

• 1 tsp dried thyme

• ½ tsp garlic powder

For the French onion topping:

• 3 large yellow onions, thinly sliced

• 3 tbsp butter

• 2 cloves garlic, minced

• 1 tbsp brown sugar

• ¼ cup dry white wine (optional)

• 1 cup beef broth

• 1 tbsp Worcestershire sauce

• 1 tsp fresh thyme (or ½ tsp dried)

• 1 bay leaf

• 1½ cups Gruyere cheese, shredded (or Swiss cheese)

• ¼ cup fresh parsley, chopped

Instructions

Prepare the chicken:

1. Preheat oven to 375°F and lightly grease a 9×13 inch baking dish.

2. Season chicken breasts on both sides with salt, pepper, thyme, and garlic powder.

3. Heat olive oil in a large oven-safe skillet over medium-high heat. Sear chicken breasts for 3-4 minutes per side until golden brown. Remove and set aside.

Caramelize the onions:
4. Reduce heat to medium and add butter to the same skillet. Add sliced onions with a pinch of salt.
5. Cook onions slowly for 20-25 minutes, stirring occasionally, until deeply golden and caramelized. Add brown sugar in the last 5 minutes to help with browning.
6. Add garlic and cook for 1 minute until fragrant.

Build the dish:
7. Deglaze with white wine if using, scraping up browned bits. Add beef broth, Worcestershire sauce, thyme, and bay leaf. Simmer for 5 minutes to reduce slightly.
8. Return chicken to the skillet, nestling it into the onion mixture. Spoon some onions over each piece.
9. Top with cheese and transfer to the oven.

Bake:
10. Bake for 20-25 minutes until chicken reaches 165°F internal temperature and cheese is bubbly and golden.
11. Rest for 5 minutes, then garnish with fresh parsley before serving.