The most common fillings for onigiri in Japan are
sha-ke (salted salmon)
umeboshi (Japanese pickled plum)
okaka (bonito flakes moistened with soy sauce)
kombu (simmered kombu seaweed)
tuna mayo (canned tuna with Japanese mayonnaise)
tarako (salted cod roe)
Salted Salmon (sha-ke)
Salted salmon in Japan is like bacon in the West. It is easily prepared by salting and adding sake (Japanese wine ) onto the salmon slightly and grilling, broiling or it or panfrying. The flesh is then flaked and can then used as a filling.
Japanese pickled plum (Umeboshi)
Japanese pickled plum is another poplular filling put into onigiri. It is a a century-old superfood known for its intensely sour and salty taste, but goes extremely well with Onigiri. The plums are boiled and then pickled in a mixture of salt, vinegar, and rice malt. Not only are umeboshi used as filling in Japanese rice balls, they are also used in a number of different side dishes such as salads, sauces or even desserts.
Bonito flakes (Okaka)
Okaka or bonito flakes are also a popular filling for Onigiri. Bonito flakes are from drying fish and then shaving them. They are used to make dashi, Japanese fish stock and also used on grilled foods as garnish. Soaked in soya sauce, they also make a tasty filling for onigiri
Kombu
Kombu is a type of seaweed that is popular in Asian cuisine. It's often used to make dashi, which s a broth or stock. Kombu is also a popular filling for onigiri. The kombu is simply boiled or steeped in water and then cut into thin strips. It is then seasoned with soy sauce, viinegar, mirin sesame oil and topped with some sesame seeds.
Kombu is a type of seaweed that is popular in Asian cuisine. It's often used to make dashi, which s a broth or stock. Kombu is also a popular filling for onigiri. The kombu is simply boiled or steeped in water and then cut into thin strips. It is then seasoned with soy sauce, viinegar, mirin sesame oil and topped with some sesame seeds.
Tuna Mayonnaise
Tuna Mayonnaise is one of the most popular fillings for Onigiri in Japan. It doesn't sound very Japanese, but it's been around decades. The popularity of tuna mayonaise as a filling for onigiri can be attributed to its light flavor and creamy texture..Japanese people love to eat tuna with rice because they think that the two ingredients go well together, especially because they both have similar flavors and so adding some mayonaise into the filling makes it more appetizing!
Tarako or Mentaiko
Tarako and Mentaiko are both cod roe from the same fish but treated differently. Tarako and mentaiko are packed with the flavors of the sea. Taroko is salted cod roe whilst Mentaiko is made much more complicated with more seasoning and ingredients. Both can be served as a side dish and in many different dishes as well. Both are popular for stuffing into onigiri, although tarako is more favored over mentaiko
