Preheat oven to 325 degrees. Cream together butter and sugar until light and fluffy. Add eggs and mix well. Thoroughly combine flour, soda, and salt. Stir in the flour mixture until well blended. Add a little more flour if necessary to make a slightly stiff dough.
Stir in chocolate and nuts. Drop dough by heaping teaspoons 5 cm apart on ungreased baking sheets. Flatten each cookie slightly. Bake 13-15 minutes. Cool cookies a few minutes on baking sheet before transferring to rack to cool completely.