Step 1: Prepare the Chicken : Season chicken breasts generously with salt and pepper on both sides. Heat olive oil or butter in a large skillet over medium-high heat. Sear chicken for 4–5 minutes per side, until golden brown. Remove from skillet and set aside.

Step 2: Sauté Aromatics : In the same skillet, add onion and sauté for 2–3 minutes until translucent. Add garlic and cook for another 1 minute until fragrant.

Step 3: Cook the Mushrooms : Add sliced mushrooms and thyme to the skillet. Cook for 5–7 minutes, stirring occasionally, until mushrooms are tender and lightly browned.

Step 4: Make the Cream Sauce : Pour in chicken broth to deglaze the pan, scraping up any browned bits from the bottom. Reduce heat to medium-low and stir in heavy cream and Parmesan cheese. Simmer for 2–3 minutes until the sauce thickens slightly.

Step 5: Combine Chicken and Sauce : Return chicken breasts to the skillet. Spoon sauce over the chicken and simmer for 3–5 minutes, until chicken is cooked through and internal temperature reaches 165°F (74°C).

Step 6: Garnish and Serve : Sprinkle with fresh parsley if desired. Serve hot over rice, pasta, mashed potatoes, or quinoa.