It is used in Korean cooking. Outside of Korean cooking, you can use it as a seasoning, or to coat meat or vegetables in.
To make: toast 1/4 cup (2 oz / 50g) of sesame seeds. Let the seeds cool, then crush them in a food processor or in a mortar and pestle, or a spice or coffee grinder, taking care not to make sesame paste. Then stir in 1 tablespoon of finely ground salt (table salt)