Step 1: Prepare Mashed Potatoes - Peel and cube the potatoes, cover with cold salted water in a large pot, bring to a boil, and cook until fork-tender. Drain, mash with butter and milk.

Step 2: Glaze Carrots - Combine baby carrots, butter, brown sugar, and a splash of water in a saucepan. Cover and simmer until tender, uncovering for the last few minutes to thicken the glaze.

Step 3: Cook Chicken - Season chicken with salt, pepper, garlic powder, thyme, and rosemary. Heat oil and butter in a skillet, sear chicken until golden and cooked through.

Step 4: Make Herb Cream Sauce - Sauté minced garlic, add chicken broth, reduce heat, then stir in cream, Parmesan, and optional mustard. Simmer until thickened.

Step 5: Return Chicken to Pan - Place chicken back in the skillet, coat with sauce, and simmer for an additional two minutes.

Step 6: Assemble and Serve - Serve mashed potatoes with the chicken and glazed carrots, drizzle sauce over, and garnish with parsley or chives.