Brown chicken in oil. Put in skillet. Add all ingredients except last 4. Cover and simmer 45 minutes. Remove chicken and take meat off bones. Beat yolks and mustard together. Stir in 3 Tbsp. of chicken cooking juices. Blend. Return yolks to the rest of the liquid in skillet. Cook slowly until slightly thick. remove from heat. Blend in sour cream. Add chicken and Fines Herbes. Heat slowly to warm.