In a bowl whisk together flour, cocoa powder and baking soda. In another bowl, with an electric mixer, beat together butter and sugar until light and fluffy. Add eggs and beat until combined well. Stir in flour mixture to form a stiff dough. Stir in nuts and chips.
On prepared baking sheet, with floured hands, form dough into two slightly flattened logs, each 12 inches long and 2 inches wide.
Bake logs for 20 - 25 minutes or until slightly firm to the touch.
Cool biscotti for 5 minutes.
On a cutting board, cut biscotti diagonally into 3/4 inch slices.
Place biscotti cut side down on baking sheet and bake until crisp, about 10 minutes.