Start by seasoning the chicken breasts generously with salt, freshly ground black pepper, dried thyme, and paprika on both sides.
In a large skillet, heat the olive oil over medium-high heat. Once the oil is shimmering, carefully add the seasoned chicken breasts. Sear each side for about 5-7 minutes, or until they are golden brown and fully cooked through. Remove the chicken from the skillet and place it on a plate, allowing it to rest.
In the same skillet, reduce the heat to medium and add the unsalted butter. Once melted, add the chopped onion. Sauté for about 3-4 minutes until the onion becomes translucent and fragrant. Then, stir in the minced garlic and sliced mushrooms. Cook this mixture for an additional 5 minutes, or until the mushrooms become soft and develop a golden color.
Pour in the chicken broth, stirring to combine, and bring the mixture to a gentle simmer. Allow it to cook for about 3-4 minutes so that it reduces slightly. After that, lower the heat further and incorporate the heavy cream, stirring continuously for an additional 2-3 minutes until the sauce is heated through and creamy.
Carefully place the seared chicken breasts back into the skillet, spooning the mushroom sauce over each piece. Allow everything to simmer together for another 5 minutes.
Before serving, garnish the dish with freshly chopped parsley for a burst of color and freshness. Taste the sauce and adjust the seasoning with more salt and pepper if needed.
Notes
For an elegant presentation, serve over rice or pasta and garnish with parsley.