French Onion Chicken
Ingredients
Sweet onions: 2 large (such as Vidalia), thinly sliced
Boneless, skinless chicken: 2 pounds (breasts or thighs)
Beef stock or broth: 2 cups
Swiss or Gruyère cheese: 1 cup, shredded (Gruyère for extra richness)
Extra-virgin olive oil: ⅓ cup, divided
All-purpose flour: 2 tablespoons, for thickening the sauce
Balsamic vinegar: 2 teaspoons
Dried thyme: ½ teaspoon
Dried sage: ½ teaspoon
Kosher salt and freshly ground black pepper: to taste
Instructions
1. Heat the oven.
Preheat the oven to 350°F (175°C).
2. Caramelize the onions.
Warm 2 tablespoons of the olive oil in a large oven-safe skillet over medium heat.
Add the onions and a pinch of salt.
Cook for 15–20 minutes, stirring now and then, until soft and deep golden brown.
Stir in the balsamic vinegar and cook for another 3–5 minutes, until the onions are dark and jammy but not burnt.
Transfer them to a bowl.
3. Sear the chicken.
Add the rest of the olive oil to the skillet and raise the heat to medium-high.
Season the chicken with salt, pepper, thyme, and sage.
Sear it on both sides until golden brown; it doesn’t need to be cooked through yet.
Move the chicken to a plate.
4. Make the gravy.
In a small bowl, whisk the flour with about ¼ cup of the beef broth until smooth.
Pour the rest of the broth into the hot skillet, scraping up all the browned bits.
Bring to a boil, then lower the heat and whisk in the flour mixture.
Simmer for 5–7 minutes, stirring often, until the sauce thickens.
5. Assemble.
Return the onions and chicken (with any juices) to the skillet and turn the chicken to coat it in the sauce.
Scatter the shredded cheese generously over the top.
6. Bake.
Transfer the skillet to the oven and bake for 15–20 minutes, until the chicken reaches 165°F (74°C) inside and the cheese is melted and bubbling.
7. Serve.
Serve hot with mashed potatoes, crusty bread, or a simple green salad.
Tip: Mixing the flour with a little broth before adding it keeps the gravy smooth and lump-free.