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.
Tuna Mayonnaise is extremely easy to make. The filling recipe calls for canned tuna and mayonnaise. Simply open a can of tuna, drain off the oil or water, add mayonnaise, salt and pepper and you have a basic rice ball filling.
There are also many variations that arise, like adding shallots, pickles, garlic, celery...anything you like. Just remember to chop them finely before mixing into the tuna.
And if you like your onigiri filling to be spicy, add a dash of paprika or chilli powder!
Easy Tuna Mayonaise Recipe (filling for 8 onigiri)
1 can (5 oz) tuna
1/8 cup mayonaise
1 TBSP finely chopped shallots
1 TBSP finely chopped fresh parsley
1 tsp sesame seeds
salt and pepper to taste
Open the can of tuna and drain off all the liquid. Try to drain out as much liquid as possible, otherwise the filling will be wet and this might leak too much liquid into the rice.
Add the shallots, parsley and sesame seeds into the tuna and mix well.
Add the mayonaise into the tuna mixture and season with salt.
You cran now fill your onigiri with this delicious traditional traditional rice ball filling. Keep in the refridgerator until ready to use. Keeps fresh for a week in the fridge.
When making the onigiri, don't put too much filling. If you have too much filling, the onigiri might fall apart when you eat it and it won't hold!