In a large skillet, heat the olive oil over medium heat. Add the sliced onions, sprinkling with a pinch of salt, and sauté for about 10-15 minutes, or until they become golden brown and caramelized.

While the onions are cooking, season the chicken breasts with garlic powder, thyme, salt, and pepper on both sides.

Once the onions are caramelized, push them to the side of the skillet and add the seasoned chicken breasts to the pan. Cook for about 5-7 minutes on each side, until they are golden brown and cooked through.

Pour in the beef broth and let it simmer for a couple of minutes, scraping the bottom of the pan to get all those delicious brown bits. Then, stir in the heavy cream.

Sprinkle the shredded cheese over the chicken and cover the skillet. Allow it to cook for another 5 minutes until the cheese is melted and bubbly.

Remove from heat, and serve the chicken with the creamy onion sauce draped over the top. Pair it with rice, pasta, or a green salad for a complete meal!