First, pound the chicken breasts to an even thickness of about ¾ inch. This ensures even cooking and tender results.
In a medium bowl, whisk together Dijon mustard, honey, olive oil, minced garlic, thyme, salt, pepper, and paprika until well combined.
Reserve about ¼ cup of the glaze for basting later. Use the remaining mixture to coat the chicken breasts thoroughly.
Let the chicken marinate for at least 30 minutes (or up to 4 hours) in the refrigerator.
Preheat your grill to medium-high heat (around 375-400°F).
Clean and oil your grill grates to prevent sticking.
Place the chicken on the grill and cook for 6-7 minutes on each side, or until the internal temperature reaches 165°F.
During the last 2-3 minutes of cooking, brush the reserved glaze on both sides of the chicken.
Let the chicken rest for 5 minutes before serving to retain its juices.