Preheat oven to 425°. Place chicken breast halves in a zip-top plastic bag. Combine buttermilk and egg. Add egg mixture to bag; seal. Marinate in refrigerator 4 hours. Remove chicken from bag; discard marinade. Sprinkle chicken with salt and pepper. Combine flour and finely ground pecans. Dredge chicken in flour mixture; shake off excess. Heat a large ovenproof skillet over medium-high heat. Add canola oil to pan; swirl to coat. Add chicken to pan; sauté for 4 minutes or until browned. Turn chicken over. Place skillet in oven; bake at 425° for 10 minutes or until done.