CHICKEN WELLINGTON

Steps:

• 1. Sprinkle chicken with 1/4 teaspoon salt and 1/8 teaspoon pepper. Melt half the butter in large skillet over medium heat. Cook half the chicken until golden, 6 minutes, turning once. Transfer to clean plate. Cook remaining chicken; cool. Melt remaining butter in skillet over medium heat. Add mushrooms and onion. Cook and stir about 5 minutes. Add wine, if desired, thyme, 1/2 teaspoon salt and 1/8 teaspoon pepper. Simmer until liquid evaporates, stirring often, 10 minutes; cool. Roll pastry to two 15 × 12-inch rectangles. Cut each into 12 × 5-inch strips. Cut corners from pastry and cut into decorative shapes. Beat egg white; brush over pastry. Place a chicken breast lengthwise at one end of each strip. Spread mustard over chicken; top with mushroom mix. Fold pastry over top. Fold bottom pastry edge up over top; seal. Place on ungreased baking sheet. Decorate with pastry shapes. Mix egg yolk with milk; brush over pastry. Cover loosely with plastic wrap. Chill until cold, 1 to 4 hours. Preheat oven to 400°F. Remove plastic wrap. Bake until golden brown and chicken is 170°F, about 25 to 30 minutes.