Preheat oven to 375 degrees.
Place the chicken breasts on a baking sheet. Season both sides with black pepper. Brush the top of each breast with 1/2 tablespoon of mustard and sprinkle pecans on top of the mustard. Bake the chicken for 20-25 minutes or until cooked through. Transfer to a cutting board and let rest for 5 minutes. Cut chicken into 1/4-inch slices crosswise.
In a small bowl, stir together the remaining tablespoon of mustard, mayonnaise and honey. Lightly coat both sides of the hamburger bun with the mustard sauce. Lay 3 or 4 slices of chicken on the bottom of the bun. Top the chicken with 2 pieces of bacon, lettuce, red onion slices, a tomato slice and the top half of the bun. Repeat with remaining ingredients.
Nutrition information per serving:
Calories340Fat13 gSodium600 mg
Carbohydrates27 gSaturated fat3 gCalcium74 mg