Preheat your oven to 375°F (190°C). In a bowl, whisk together the Dijon mustard, whole grain mustard, honey, olive oil, garlic, paprika, salt, and pepper until well combined.
Place the chicken breasts in a baking dish. Pour the honey mustard sauce over the chicken, ensuring they are evenly coated. Use a spoon or brush to spread the sauce all over.
Bake in the preheated oven for 30–35 minutes, or until the chicken is cooked through and reaches an internal temperature of 165°F (74°C). Baste with the sauce halfway through for extra flavor.
Let the chicken rest for 5 minutes before serving. Garnish with chopped parsley and spoon extra sauce from the pan over the top.