1. Preheat oven to 425°.
2. Place a wire rack on a baking sheet; coat with cooking spray. Combine mustard and egg in a shallow dish, stirring with a whisk. Combine panko, hazelnuts, and sage in a shallow dish. Sprinkle chicken evenly with 1/4 teaspoon pepper and salt. Dip chicken in egg mixture; dredge in panko mixture, pressing to adhere.
3. Heat a large nonstick skillet over medium-high heat. Add 1 tablespoon olive oil to pan, and swirl to coat. Add chicken, and cook 2 minutes on each side or until browned. Place chicken on prepared rack, and bake at 425° for 12 to 15 minutes or until done.
4. Wipe skillet with a paper towel; heat over medium heat. Add remaining 1 teaspoon oil to pan; swirl to coat. Add shallots; cook 1 minute or until tender. Add remaining 1/4 teaspoon pepper, chicken stock, port, and cranberries; bring to a boil. Reduce heat to low; simmer 4 minutes or until liquid is reduced by half. Remove pan from heat. Add balsamic vinegar and butter to pan, stirring until butter melts. Spoon port mixture over chicken.