01 - Preheat oven to 400°F. Lightly grease a baking dish large enough to accommodate chicken thighs in a single layer.
02 - Pat chicken thighs dry with paper towels. Season both sides generously with salt and black pepper.
03 - In a medium bowl, whisk together Dijon mustard, whole-grain mustard, honey, olive oil, lemon juice, minced garlic, smoked paprika, and rosemary until fully incorporated and smooth.
04 - Place chicken thighs in prepared baking dish, skin side facing up. Pour honey mustard mixture evenly over chicken, ensuring each piece is thoroughly coated.
05 - Bake uncovered for 30-35 minutes until chicken reaches internal temperature of 165°F and skin is golden brown with caramelized edges.
06 - For extra crispy skin, switch to broil setting for 2-3 minutes. Watch closely to prevent burning the glaze.
07 - Remove from oven and let chicken rest for 5 minutes. Spoon remaining pan sauce over each piece before serving.
08 - Sprinkle with chopped fresh parsley. Serve hot with roasted potatoes, rice, or steamed vegetables.