A delightful casserole that marries the rich, savory notes of French onion soup with tender chicken, resulting in a meal that’s not only delicious but also incredibly satisfying.
Season both sides of the chicken breasts with salt and pepper.
In a large skillet over medium heat, melt the butter and olive oil together. Add the sliced onions and sugar, stirring frequently. Cook for about 20-25 minutes or until caramelized and golden brown. Add thyme and balsamic vinegar, cooking for an additional 2 minutes.
In a bowl, mix together the French onion soup, sour cream, garlic powder, and onion powder until well combined.
In a greased 9x13-inch baking dish, place the seasoned chicken breasts. Top with the caramelized onions, then pour the creamy sauce over the chicken.
Sprinkle the shredded Swiss cheese over the top, then add the breadcrumbs.
Cover with aluminum foil and bake for 25 minutes. Remove the foil and bake for an additional 15-20 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the cheese is bubbly and golden brown.
Remove from the oven and let it rest for a few minutes. Garnish with chopped parsley before serving.
