1. Peel and cut the potatoes into chunks, then place them in a pot of cold salted water. Bring to a boil and cook for 15 to 18 minutes, or until fork tender.

2. While the potatoes cook, pat the chicken dry and season both sides with onion powder, 1/2 teaspoon salt, and 1/4 teaspoon black pepper.

3. Heat the olive oil and 1 tablespoon butter in a large skillet over medium heat. Add the chicken and cook for 5 to 6 minutes per side, until golden brown and cooked through. Transfer to a plate.

4. In the same skillet, reduce the heat slightly and add 1 tablespoon butter. Stir in the minced garlic and thyme, cooking for about 30 seconds until fragrant.

5. Pour in the chicken broth and scrape up the browned bits from the pan. Stir in the heavy cream and Parmesan cheese, then simmer for 3 to 5 minutes until the sauce thickens slightly.

6. Drain the potatoes and return them to the pot. Add the remaining 1 tablespoon butter, the milk, the remaining 1/2 teaspoon salt, and the remaining 1/4 teaspoon black pepper. Mash until smooth and creamy.

7. Return the chicken to the skillet and spoon the sauce over the top. Let it warm through for 2 to 3 minutes.

8. Serve the chicken over mashed potatoes, spoon extra sauce over everything, and finish with parsley before serving.