1. In a large bowl, whisk together honey, Dijon mustard, olive oil, garlic, cayenne pepper or curry powder (if using), salt, pepper, and herbs if desired. For the mustard sauce option, mix together honey, chicken stock, Dijon mustard, whole grain mustard, vinegar, and sriracha.
2. Add chicken pieces to the marinade and stir well to coat evenly. Cover and refrigerate for at least 30 minutes, preferably 1 hour, or up to 24 hours for deeper flavor. Avoid piercing the chicken to retain juices.
3. Preheat oven to 350°F to 400°F (177°C to 204°C), depending on the cooking method and chicken cut. If baking bone-in thighs with skin, 350°F (177°C) for 40–45 minutes is ideal for tender, crispy skin. Boneless, skinless cuts cook faster at 400°F (204°C) for 20–30 minutes.
4. For grilling: Preheat grill to 400°F (204°C), cook chicken 6–8 minutes per side or until an internal temperature of 165°F (74°C) is reached.
5. For pan-searing and baking (especially for breasts): Sear chicken in a preheated non-stick pan with 2 tablespoons oil for about 2 minutes per side until golden, then transfer to an oven-safe dish. Pour marinade or mustard sauce over chicken and bake 15–25 minutes, until the internal temperature reaches 165°F.
6. Let chicken rest covered loosely with foil for 5–10 minutes before serving to retain juices.