Either soak in marinade overnight and place in dehydrator until crunchy or lightly toast seeds on separate trays (sunflower seeds take longer).
If you are going to toast in the oven instead of marinating before cooking, after the seeds are toasted, evenly coat each tray of seeds with half each of the soy sauce & sesame oil (use a metal spatula).
Combine the two seeds. Cool. Place in an airtight container.