In a dry skillet, lightly toast the white and black sesame seeds, sichuan peppercorns and poppy seeds until fragrant, being careful not to burn them. Transfer to a bowl and let them cool completely.
Place all of the ingredients along with the nori in a spice/coffee grinder and pulse until coarsely ground (be sure it's coarse and not a fine powder).Store in an airtight jar. For optimal flavor use within a few weeks.