In small bowl, combine pecans, honey, and mustard. Place chicken and pecan mixture in re-sealable plastic bag and shake gently to coat chicken with mixture. Marinate 5 hours or overnight.
Preheat oven to 325 degrees F. Transfer chicken to small baking dish and partially bake 15 minutes. Pour pan juices from chicken into a small saucepan. Prepare a hot charcoal fire or preheat a gas grill. While grill is heating, boil pan juices briefly until thickened and syrupy; set aside.
Grill chicken breasts over medium heat 2 – 3 minutes each side or until lightly browned and cooked through. Transfer chicken to platter, brush with thickened pan juices and serve.
Nutrition information per serving-325 calories; 35g protein; 16g carbohydrate; 2g fiber; 13g fat; 1g saturated; 82mg cholesterol; sodium: 215 mg.