In a large bowl cream the margarine and the two sugars. Beat in the egg and vanilla. Gradually blend in the dry ingredients.
Fold in the chocolate chips and the nuts. Cover and chill for 2 to 3 hours.
Drop by teaspoonfuls onto lightly greased baking trays. Bake 10-12 minutes and transfer to wire racks to cool. Take out of oven when lightly coloured - they will darken after being taken off baking tray.