Creating Herb Roasted Chicken in Creamy White Sauce with Mushroom and Potatoes is simple if you follow these steps:

1. Preheat the Oven: Preheat your oven to 400°F (200°C) to prepare for roasting.
2. Sear the Chicken: In a large oven-safe skillet, heat the olive oil over medium-high heat. Season the chicken thighs with salt and pepper. Sear them skin-side down for about 5-7 minutes until golden brown. Flip them and cook for another 3-4 minutes. Remove from the skillet and set aside.
3. Sauté Vegetables: In the same skillet, add the chopped onion and minced garlic. Sauté for 2-3 minutes until fragrant. Add the sliced mushrooms and diced potatoes, cooking for another 5 minutes until they begin to soften.
4. Make the Sauce: Pour in the chicken broth and heavy cream. Stir in the fresh thyme and rosemary. Allow the mixture to simmer for 2-3 minutes.
5. Combine Chicken and Sauce: Return the seared chicken thighs to the skillet, skin-side up, ensuring they are nestled among the potatoes and mushrooms.
6. Roast in the Oven: Place the skillet in the preheated oven. Roast for 30-35 minutes or until the chicken is cooked through and the internal temperature reaches 165°F (75°C).
7. Garnish and Serve: Once cooked, remove from the oven. Let it sit for a few minutes before garnishing with fresh parsley. Serve warm, ensuring each plate has chicken, potatoes, and mushrooms.

These steps will guide you in creating a fantastic meal that is both flavorful and satisfying.