French onion soup is one of my very favorite comfort foods. I just love it, so when I saw this recipe on Closet Cooking months ago, it stuck in my mind. My kids and husband all love French onion soup too, so I decided to finally give this recipe a try. It was amazing! We all devoured it. The sauce had so much flavor, the onions were sweet and melt in your mouth perfect, while the chicken was tender and juicy. I served this French onion chicken with a freshly baked baguette and a tossed salad. We all really loved the meal. I’ll be making this dish again!
Melt the two tablespoons of butter in a large Dutch oven over medium heat.
Add the onions and cook until deeply golden brown, about an hour. Make sure to stir often, adding a bit of beef broth to deglaze the pan as needed.
Preheat the oven to 350 degrees
Add the garlic, thyme, and flour to the onions then cook for another minute, stirring constantly. Add one cup of the beef broth, deglaze the pan making sure to scrape up any browned bits on the bottom of the Dutch oven, bring to a boil, reduce the heat and simmer for 5 minutes.
Meanwhile, heat the oil in another pan over medium-high heat. Cut each chicken breast in half lengthwise (and the thin ends off if you’d like) season each piece of the chicken evenly with sea salt, freshly cracked pepper, and garlic powder, to taste.
Add the chicken to the hot pan and brown on both sides, about 3-4 minutes per side, set aside on a plate.
Add the remaining cup of broth to the pan that you cooked the chicken in, deglaze it making sure to scrape up any browned bits off the bottom of the pan, whisk in the balsamic vinegar and mustard, bring it to a boil, then reduce the heat and simmer to reduce the sauce by half, about 5 minutes.
Pour the vinegar/mustard sauce on the onions and mix well to combine. Add the chicken and it’s juices to the onions then spoon sauce over each piece. Cover with a lid and bake in the oven for 10 minutes.
Remove the chicken from the oven and sprinkle the top with the cheese. Place back into the oven under the broiler until the cheese has melted, about 2-4 minutes. Sprinkle the top with fresh thyme leaves, if desired, and serve. Enjoy.