01 - Preheat oven to 400°F. Grease a baking dish large enough to hold chicken in a single layer.
02 - In a medium bowl, whisk together Dijon mustard, whole grain mustard, honey, olive oil, lemon juice, garlic, smoked paprika, thyme, salt, and pepper until smooth.
03 - Place chicken breasts in prepared baking dish. Pour honey mustard sauce over chicken, turning each breast to coat thoroughly.
04 - Bake uncovered for 30-35 minutes until chicken reaches internal temperature of 165°F and sauce is bubbling and slightly caramelized.
05 - For golden color, broil on high for 2-3 minutes at the end, watching carefully to prevent burning.
06 - Remove from oven and let rest for 5 minutes. Spoon sauce over chicken and garnish with fresh parsley before serving.