Preheat your Oven to 425°F. Line a large Baking Sheet with Aluminum Foil or Parchment Paper for easy cleanup. In a Mixing Bowl, Whisk together the 3 tbsp Dijon mustard, 3 tbsp honey, 1 tbsp mayonnaise, 1 tsp apple cider vinegar, and ½ tsp garlic powder until smooth. Set the glaze aside.

Peel 2 medium carrots peeled and cut into 1-inch piecess and trim the ends. Cut on a deep diagonal into ½-inch slices, or leave small 2 medium carrots peeled and cut into 1-inch piecess whole. Keep cuts consistent — same size means even cooking. Toss in a Mixing Bowl with a drizzle of olive oil until coated. Season well with kosher salt and black pepper. Add herbs or spices now if using (thyme, rosemary, garlic). Toss to coat evenly. Line a Baking Sheet with Aluminum Foil and lightly oil it.

Preheat Oven to 425°F (or 400°F for a gentler roast). Spread seasoned carrots in a single layer on a Baking Sheet — no touching or overlapping, or they'll steam instead of brown. Use two pans if needed. Roast at 425°F for 25–35 minutes, or at 400°F for 35–40 minutes. Toss every 10 minutes for even browning on all sides. For a glaze, add it in the last 5–10 minutes. Toss to coat and return to oven until absorbed and caramelized.

Pat the 4 pieces bone-in, skin-on chicken thighs patted dry dry and rub them all over with 1 tablespoon 1 tbsp olive oil, ½ teaspoon ½ tsp salt, and ¼ teaspoon ¼ tsp black pepper freshly ground. Nestle the 4 pieces bone-in, skin-on chicken thighs patted dry skin-side up among the 1 lb baby potatoes halved on the Baking Sheet. Spoon or brush about half of the 3 tbsp honey 3 tbsp Dijon mustard glaze generously over the tops of the 4 pieces bone-in, skin-on chicken thighs patted dry pieces.

Let the 4 pieces bone-in, skin-on chicken thighs patted dry rest on the pan for 5 minutes before serving. Garnish with fresh chopped 2 tbsp fresh parsley chopped if desired and serve directly from the Baking Sheet.