Season the chicken breasts with salt and pepper on both sides.
In a large skillet, heat the olive oil over medium-high heat. Add the chicken breasts and cook for about 6-7 minutes on each side, or until golden brown and cooked through. Remove the chicken from the skillet and set aside.
In the same skillet, reduce the heat to medium and add the butter. Once melted, add the sliced mushrooms and sauté for about 5 minutes, or until they are browned and tender.
Add the minced garlic to the skillet and cook for an additional 1 minute, stirring frequently to prevent burning.
Pour in the chicken broth and add the dried thyme. Bring the mixture to a simmer and let it cook for about 3-4 minutes, allowing the sauce to reduce slightly.
Return the cooked chicken to the skillet, spooning the mushroom sauce over the top. Cook for an additional 2-3 minutes to heat the chicken through.
Garnish with fresh parsley before serving.
Notes
For a creamier sauce, stir in 1/4 cup of heavy cream after adding the chicken broth.
Serve the chicken and sauce over cooked rice or pasta for a more filling meal.