With the help of a modern food processor, making this aromatic dip is a simple matter. In Japan, sesame seeds were traditionally ground in a mortar called a suribachi, and it took determination and strength to make quantities such as these. This sesame dip is deliciously nutty and aromatic when first made, though it will stay fresh for many weeks if refrigerated. To restore some of the original flavor, should it begin to fade, stir in an extra teaspoon of dark sesame oil.