Shichimi togarashi is a Japanese 7-spice blend that typically includes red chile flakes, dried orange peel, white sesame seeds, black sesame seeds, nori (seaweed) flakes, poppy seeds and ginger. Actual ingredients may vary depending on the brand. Use the mixture to flavor soups or noodles and yakitori.
This ingredient can be found in most any Japanese and some other Asian grocery stores. You can also purchase it online through Gourmetsleuth, see buy link under the image. You can also find it from various sellers on Amazon.com.
For a substitute, you can make your own. See recipe below or:
Grind the white sesame seeds and sansho coarsely in a suribachi or other a small electric spice grinder. Now add the tangerine peel, and grind again.
Stir in the remaining spices and blend them together well.
You can keep the shichimi togarashi In an airtight container, the mixture will keep for 3-4 months.