Instructions

  1. Preheat oven to 350ºF.
  2. In a medium-size saucepan, melt butter over medium heat.
  3. Stir in flour and cook, stirring, for 1 minute without browning.
  4. Whisk in milk, bring to a boil, and cook, stirring, until sauce is thick and smooth, about 3 minutes.
  5. Stir in horseradish, sour cream, sugar, mustard, and vinegar.
  6. Season with salt and pepper to taste.
  7. Arrange chicken breasts, skin side up, in a baking dish.
  8. Spoon half the horseradish sauce over chicken.
  9. Bake 45 minutes until chicken is tender.
  10. Broil chicken for 5 minutes to brown.
  11. Reheat remaining sauce and serve over chicken.