1. In a large skillet or Dutch oven, melt 2 tablespoons (30g) of butter over medium heat. Sauté 1 large onion, sliced, until softened and translucent.

2. Add 1 pound (450g) of chicken pieces to the skillet and cook until browned on all sides, about 5 minutes. Remove the chicken from the heat and set it aside.

3. In the same skillet, add 8 ounces (225g) of mushrooms and cook over medium heat until they release their liquid and start to brown, about 3-4 minutes.

4. Add 2 cloves of minced garlic, 1/2 teaspoon of cayenne pepper, and 1/2 teaspoon of dried thyme to the skillet. Cook for an additional 1 minute, stirring constantly.

5. Pour in 1/2 cup (120ml) of dry white wine and cook over medium heat until the liquid has almost completely reduced, about 5 minutes.

6. Add 1 cup (250ml) of veal broth and 1/2 cup (120ml) of water to the skillet. Return the browned chicken to the skillet and bring the mixture to a boil.

7. Reduce the heat to a gentle simmer, cover the skillet, and cook for 20-25 minutes, or until the chicken is cooked through and reaches an internal temperature of 165°F (74°C).

8. Stir in 1/2 cup (120ml) of heavy cream and cook for an additional 2-3 minutes, or until the sauce has thickened slightly.

9. Season the sauce with salt and white pepper to taste.

10. Serve the chicken and sauce over boiled potatoes, garnished with chopped parsley and a sprig of rosemary.