Put 2 teaspoons of grapeseed oil into a non-stick frying pan over medium heat. When hot, add 1 sheet of the layered kombu and fry until lightly golden on both sides. Remove and drain. Repeat with the remaining kombu sheets, adding more oil as necessary. Allow to cool completely.
In a mixing bowl, break the layered kombu into small rough pieces, approximately 5 mm (¼ inch) square. Repeat with the toasted nori and rice lace. Add sesame seeds and the shiitake skins and mix well. Store in an airtight container until required.