Before coming to Japan, I wasn’t very knowledgeable about sushi. I had eaten sushi in “Japanese” restaurants (Chinese people, not Japanese people, run most of the ones in western countries). I had eaten “sushi rolls” (makizushi, 巻き寿司) and “sashimi” (nigirizushi, 握り寿司) but I couldn’t really tell you what was typical. You couldn’t expect me to talk about any other type either because I had never seen them before. One of those types that I would like to share with you today is Oshi Sushi (“box sushi” or “pressed sushi”).
What is Oshi Sushi?
For Oshi Sushi, as the name implies, you put the ingredients into a box and pressed them; the difference is that other types of sushi are made by hand. Oshi Sushi originally comes from having to store fish and other foods before refrigeration. A good way of storing them was to put them in boxes and fill the boxes with rice. This kept moisture and other things that may spoil the ingredients from getting to them. Over time Oshi Sushi was born in a place called Osaka.
Today with refrigeration we no longer need to store food in this way but it has become a nice way to make and eat sushi. You need the same things to make any other sushi but you also need a box called an oshizushihako (押し寿司箱). If you don’t have one, don’t worry! With a couple of pieces of wood and some screws, you could make it for yourself. I also recommend a sander so you don’t get splinters!
The box looks like this:
The box is made of three pieces: the lid (not shown above), the sides and the base. Each piece is free of the others. The bottom is also raised slightly; the lid has handles for you to hold and push gently. Easy to make if you are a crafty person!
Let’s get to the recipe! To make Oshi Sushi, you will need the following ingredients:
- Cooked Japanese Rice
- something to put on top of the sushi – typically salmon, mackerel, tuna and other fish used for sushi, Japanese egg omelette, vegetables
The exact amounts that you need of each ingredient vary depending on how much you are making and what kind of flavours you would like. Read the recipe and then decide for yourself how much of each you would like.
A quick note before we begin: you will be mixing the mirin, salt and sugar with the rice. We want to give the rice some flavour without it losing its sticky quality, so we don’t need much of these ingredients. For 1kg cooked rice, I used maybe 100 mL of this mixture. Depending on your tastes, you can also add more or less salt and sugar. Since mirin is the only liquid, use the total volume of mirin and add salt and sugar, tasting as you go. The total volume will also decrease.
Preparing Oshi Sushi
Step 1: Make the rice
If you are unfamiliar with how to cook Japanese rice, you should first read How to make Japanese Rice – a guide by Just One Cookbook. This will take you through the steps. This is very important for all types of sushi and sushi-like foods as the rice needs to be prepared a certain way. It needs to have the right consistency and stickiness. “Any old rice cooked any old way” won’t do.
Step 2: Make the rice mixture
Once the rice is done (or cooling), the next step is to make the mixture to give the rice some flavour. Put the mirin (see the note above in the ingredients section) in a small saucepan and bring it to a boil. Add the sugar and salt and mix until fully dissolved. When it starts to thicken a bit, turn off the heat and let it cool.
Step 3: Prepare the rice
Now that the rice and mixture have cooled, put the rice into a flat bowl, and sprinkle your desired amount of sesame on the rice. Using a rice paddle (a wooden spoon or spatula will also do), cut the rice. By this I mean put the paddle sideways into the rice and move it in a straight line. Then pick it up and do the same thing. DO NOT STIR THE RICE! This will break up the rice and it will not be sticky. We need it to be sticky or it won’t work correctly.
Once sufficiently mixed, add the mirin-salt-sugar mixture to the rice and cut again until mixed evenly. This should not take long as you make very little of the mixture and it will be soaked up by the rice. The rice should not really change colour since you used so little mixture.
Step 4: Layers and pressing
It is time to start building your culinary masterpiece! Before you start, a good tip is to have a bowl of water next to you. If things start to stick, wet them with water from this bowl using your hand.
You can start one of two ways: add rice to the box and then your ingredients or vice versa. If you add the rice first, fill it up most of the way and then add a layer of your sushi topper(s). If you do it the other way around, put the sushi topper layer on the bottom and then fill the box with rice. Make sure in either case that it is not overflowing! If it is, you will have a very difficult time and it will be messy. Easier to not do it and just make more!
Once you have done this, add the lid. Gently press down until the lid is below the walls and there is resistance. Once you are at this point, remove the walls (they slide up around the lid so you are left with just the lid and the base attached to the sushi. Now we are going to transfer it to your serving surface (e.g. fancy restaurant slate, cutting board, serving plate, etc.).
At this point, you might find that one side or the other sticks. If this happens, don’t panic. Simply use a knife and try to remove the part that is sticking before you move the lid or base. If you try to remove either without testing it, you may find that the sushi falls apart.
Here is a video of it being done:
You are all done! Enjoy the amazing, easy-to-make sushi that you just created!
Want more food? Check out my interactive Travelling the World map for food from around the world! You can also find more food that I have made following Just One Cookbook and Nami here.