Ingredients:
- 4 boneless, skinless chicken breasts (about 1.5 lbs or 680g)
- Salt and pepper, to taste
- 2 tablespoons olive oil (30ml)
- 2 large yellow onions, thinly sliced
- 3 cloves garlic, minced
- 1 teaspoon fresh thyme leaves (or ½ teaspoon dried thyme)
- 1 tablespoon balsamic vinegar (15ml)
- ½ cup chicken broth (120ml)
- 1 cup Gruyère cheese, shredded (about 100g)
- Fresh parsley, chopped for garnish (optional)
Instructions:
- Season chicken breasts with salt and pepper.
- Heat olive oil in a large skillet over medium heat.
- Sauté chicken until golden brown, about 5-7 minutes per side. Remove chicken and set aside.
- In the same skillet, add sliced onions and a pinch of salt; cook until onions are caramelized, stirring occasionally (about 12-15 minutes).
- Add garlic and thyme, sauté for an additional minute.
- Pour in balsamic vinegar and broth, scraping up any browned bits; simmer for 2-3 minutes until slightly reduced.
- Return chicken to the skillet, nestling in the onion mixture; top each chicken breast with shredded Gruyère cheese.
- Cover and cook until cheese is melted and chicken is cooked through (about 5 minutes). Internal temperature should reach 165°F (74°C).
- Garnish with fresh parsley before serving.