Start by peeling and cubing your Yukon Gold or Russet potatoes. Place them in a pot of cold, salted water, bringing it to a boil over medium-high heat. Cook the potatoes for about 15–20 minutes, or until fork-tender. Drain and return them to the pot, adding warm milk and butter. Mash until creamy and season generously with salt and pepper.

While the potatoes simmer, prepare the carrots. In a skillet over medium heat, combine sliced carrots with butter, brown sugar, and a pinch of salt. Cover the skillet and let the carrots simmer for 10–12 minutes until they are tender and beautifully caramelized. Stir occasionally to ensure even cooking and prevent burning.

Pat the chicken breasts or thighs dry before seasoning with salt and pepper. In a large skillet, heat olive oil and a tablespoon of butter over medium-high heat. Add the chicken to the hot skillet and sear for about 4-5 minutes on each side until golden brown and cooked through. Remove the chicken from the skillet and set aside to rest.

In the same skillet, reduce the heat to medium and add minced garlic, sautéing for about 1 minute until fragrant. Carefully deglaze the pan with chicken broth, scraping up any flavorful bits. Stir in the heavy cream and Dijon mustard, if using, letting it simmer for 3-4 minutes until the sauce thickens. Return the cooked chicken to the skillet, coating it with the creamy herb sauce.

To plate, create a fluffy base of mashed potatoes in the center of each plate. Top with the creamy herb chicken, ensuring each piece is generously drizzled with sauce. Arrange the sweet glazed carrots on the side, and sprinkle fresh parsley or thyme for a burst of color and freshness. Serve immediately.