Cream butter and sugar together.
Blend in the coffee, add the flour gradually and mix thoroughly.
Roll out 1/2 inch thick and cut into 1/2 X 2-inch fingers.
Dip fingers in slightly beaten egg white, then roll in finely chopped nuts.
Place on ungreased baking sheets.
Bake at 300F for 20 to 25 minutes.
Store in a covered tin, with wax paper between each layer of cookies.