Grandmom'S Christmas Cookies
["2 1/2 c. flour", "1/2 lb. butter", "1 egg, separated", "3/4 c. sour cream", "2 c. ground pecans", "1 c. sugar", "milk", "confectioners sugar"]
["Measure into bowl the flour and butter", "Cut butter into flour with fingertips.", "Then add egg yolk, and sour cream.", "Mix well and shape into ball.", "Sprinkle with flour and knead until smooth. Chill dough for 20 minutes.", "Prepare filling."]
["flour", "butter", "egg", "sour cream", "ground pecans", "sugar", "milk", "confectioners sugar"]