Natto tuna

Fresh tuna with natto (fermented soybean), sesame oil, green onion, cucumber, and smelt roe.
What's Natto?
Nattō (なっとう or 納豆?) is a traditional Japanese food made from soybeans fermented with Bacillus subtilis. It's a rich source of Protein, and provides Vitamin B12 that tends to lack in vegetarian diet.