2 c. sifted all-purpose flour
1 tsp. baking soda
1 tsp. cream of tartar
1/4 tsp. salt
1/2 c. butter
1/2 c. vegetable shortening
1/2 c. light packed light brown sugar
1/2 c. granulated sugar
1 egg
1 tsp. vanilla
3/4 c. walnuts, coarsely chopped
1 (6 oz.) pkg. semi-sweet chocolate pieces

Bake at 350 degrees for 12 to 15 minutes. Combine flour, baking soda, cream of tartar and salt in small bowl. Cream butter, shortening and sugars in large bowl. Add egg; beaten well. Add vanilla. Add flour mixture; blend well. Stir in walnuts and chocolate pieces. Drop by rounded teaspoon onto lightly greased cookie sheets.