Place peeled and chopped Yukon Gold or Russet potatoes into a large pot and cover with cold water by about 1 inch. Stir in 1 ½ teaspoons of kosher salt and bring the water to a boil over medium-high heat. Reduce to a gentle boil, cooking for 15–20 minutes until the potatoes are tender. Drain the potatoes, returning them to the pot to steam dry for 1–2 minutes.

In a small saucepan, warm ½ to ¾ cup of milk over low heat. Meanwhile, add 4 tablespoons of unsalted butter to the drained potatoes and mash until mostly smooth. Gradually stir in the warm milk along with sour cream or cream cheese if desired. Season with ½ teaspoon of salt and ¼ teaspoon of pepper, then keep warm while you prepare the rest of the dish.

Pat the 4 boneless, skinless chicken breasts dry using paper towels. Sprinkle with 1 teaspoon of kosher salt, ½ teaspoon of freshly ground black pepper, garlic powder, and onion powder. Gently rub the seasoning into the chicken to fully coat each piece.

Heat a skillet over medium-high heat, adding 2 tablespoons of olive oil and 1 tablespoon of unsalted butter. Once hot, place the seasoned chicken breasts in the skillet. Sear for 4–5 minutes on each side until golden brown and the internal temperature reaches 68–70 °C (155–160 °F). Transfer the chicken to a plate and cover loosely with foil to keep warm.

In the same skillet, combine sliced carrots, 2 tablespoons of unsalted butter, brown sugar or honey, and ¼ cup of water or orange juice. Add a pinch of kosher salt and freshly ground black pepper, mixing well. Simmer the carrots over medium heat for about 6–8 minutes while stirring to ensure an even coating. Remove the lid and continue cooking for another 3–5 minutes until they are beautifully glazed.

Lower the heat to medium in the skillet, adding 1 tablespoon of butter. Once melted, add the minced shallot and sauté for 1–2 minutes until they become translucent. Stir in the minced garlic and cook for 30 seconds. Pour in the dry white wine (or broth) and simmer until reduced by half, about 2-3 minutes.

Stir in 1 cup of low-sodium chicken broth and 1 cup of heavy cream into the skillet. Add 1 teaspoon of Dijon mustard and the remaining ½ teaspoon of black pepper. Allow the sauce to simmer for 4–6 minutes, stirring occasionally, until it begins to thicken. Optionally, mix in ¼ cup of freshly grated Parmesan cheese for an extra creamy finish.

Return the seared chicken to the skillet, spooning the creamy sauce over each piece. Simmer on low for an additional 4–6 minutes until the chicken reaches an internal temperature of 74 °C (165 °F). Allow the chicken to rest in the sauce for 3–5 minutes to absorb the rich flavors before serving.

On each plate, serve a generous portion of creamy mashed potatoes, a succulent piece of chicken draped in herb sauce, and a side of glossy glazed carrots. Garnish with chopped fresh herbs as desired.