Preheat your oven to 425°F exactly, positioning the rack to the center. Pat your chicken pieces completely dry with paper towels—this creates the crispy exterior that distinguishes restaurant-quality results from standard home cooking.

Combine minced garlic, fresh rosemary, thyme, Dijon mustard, lemon juice, olive oil, sea salt, and paprika in a small bowl, whisking thoroughly until the herbs distribute evenly. This marinade should look fragrant and vibrant, with visible herb specks throughout.

Rub the herb mixture generously over every chicken piece, ensuring the marinade coats all surfaces including underneath thighs. This step determines flavor intensity across your entire dish.

Arrange chicken pieces skin-side up in a large roasting pan, spacing them evenly without crowding. Add sliced onion, halved baby potatoes, and carrot pieces around the chicken in the pan. Pour chicken broth into the bottom of the pan carefully, avoiding direct contact with herb coatings.

Roast at 425°F for exactly 28 minutes until the chicken begins showing golden-brown coloring on the skin. Juicy rosemary herb chicken requires precise timing here—undercooking risks food safety while overcooking dries the meat.

Remove the pan from the oven and dot butter pieces over the chicken skin, distributing them strategically across each piece. Return to the oven for the final 2 minutes, allowing the butter to melt and create that glossy, showstopping appearance.

Check internal temperature at the thickest thigh section—it should read 165°F on an instant-read thermometer. If any pieces haven't reached temperature, continue roasting in 1-minute increments while monitoring closely.

Rest the pan on your countertop for 5 minutes before serving, allowing juices to redistribute throughout the meat for maximum tenderness and flavor retention.