Sweet Potato Tempura Maki Sushi Rolls

Creamy roasted sweet potato, fresh avocado and crunchy tempura flakes wrapped in nori and sushi rice. Sushi chefs may train for years to make the perfect sushi, but you don’t need perfection to make delicious sushi at home - no raw fish required! It takes a bit of practice but once you master a few steps and techniques, homemade sushi is no more difficult or time consuming than any other special weekend meal. 

Is it Sushi Without Raw Fish?

If you’d like to try making sushi at home but you don’t eat fish or you don’t want to serve raw fish at home the good news is - you don’t need it. Sushi refers only to vinegared rice paired with toppings.

No one knows for sure how old sushi is, but it’s believed to have been invented by peoples of inland regions of Southeast Asia who practiced rice paddy agriculture and depended on freshwater fish as a dietary staple, but, living away from the ocean, could not depend on a year-round supply. Sushi was created as a strategy for long-term food storage.

In its original form, sushi was fermented rice and salt-cured seafood. The rice would break down completely during a process of lactic-acid fermentation, which could take a year or more, and become so sour it was inedible. Its purpose was to protect the cured fish inside, not to be eaten. That changed when, after sushi was widely adopted in Japan, where at least some wealthier people had relatively reliable access to fish, a shorter fermentation process developed that retained the integrity of the rice. Eventually, when the invention of rice vinegar in the early 1600s rendered fermentation unnecessary for achieving mildly tart rice, sushi could be made and eaten immediately; eaten for pleasure, not survival. 

But raw fish as a topping is a relatively new addition in the history of sushi, popularized only after refrigeration became widespread. Cured or cooked seafood and vegetables have been more common accompaniments to the rice component of sushi than raw fish. Especially in the case of rolled sushi, or maki, which wasn’t created until the late 1700s and was primarily sold as street food using simple inexpensive ingredients like eggs, pickles and vegetables.

The Story of Sushi

Oishi: The History of Sushi

Tips for Making Sushi Rice

Use the right kind of rice

For making sushi, you want to use a Japanese short-grain rice, often specifically labeled “sushi rice.” 

Sure, it’s possible to use other types of rice, including brown rice if you want to add more fiber to your sushi, but you won’t get the right sticky texture and your rolls won’t hold together as well. If you go this route you’re probably best off doing a nori-on-the-outside roll, rather than the inside-out roll technique described in this recipe.

Don’t open the lid! 

There are a number of steps to getting this sushi rice recipe right:

1. Let the rice sit in the pot with the water, lid on, for 10 minutes
2. Turn the heat to medium, bring to a boil
3. Turn the heat up to medium-high, 5 minutes
4. Turn the heat to low, 10 minutes
5. Remove from heat, 10  minutes 

These are easy steps, but you have to get the hang of doing them. The important thing is to keep a tight fitting lid on the pot the entire time. Don’t lift it to peek in! If you do, you can let out the steam and your rice can come out overcooked and lumpy. Using a pot with a glass or otherwise transparent lid makes it a lot easier to get your sushi rice right, because you can use visual cues to figure out when the water has come to a boil.

Tips for Rolling Sushi

Moisten Hands and Knife

When making sushi, anytime you’re handling the sushi rice you want to keep your hands and your knife moist. Sushi rice is sticky, it sticks to everything dry that it touches, which becomes frustrating fast. Before assembling your sushi, set a small bowl of water next to your work station and dip your hands or your knife into it before either will be touching the sushi rice.

Rice on Rough Side of Nori

Your nori will have a rough side and a shinier smooth side. When assembling your rolls, the sushi rice should always be placed on the rough side of the nori.

Use the Right Amount of Rice

How much rice you use for each roll depends somewhat on personal preference. I like to use about 125 grams of sushi per roll (which is about 1 heaping ½ cup of rice). When you figure out how much rice you like and you make sushi a few times, you’ll be able to easily eyeball the amount you need. 

Use a Sharp, Clean Knife. 

Make sure the knife you use is sharp. Then, when you cut through your sushi roll, don’t press the knife down too firmly, that can squish the roll. Instead, use a gentle back-and-forth sawing motion. Finally, make sure to wipe any residue off your knife and dip it back into the bowl of water before each cut - the knife should be clean each time it touches the sushi roll.

Don’t overfill the sushi. 

You want the rice to meet all the way around the outside of the rolls to make sure they hold together. If it’s too stuffed, your sushi will still taste great, but will fall apart as you eat it. This will be somewhat trial and error and somewhat personal preference to get the ratio of fillings to rice correct, but I like to use about 3 fillings and keep them each about ¼ - ½ ” thick.  

Make it Easier

I’m not going to lie, don’t make sushi if you are looking for a quick easy meal. It takes preparation and technique, and there is a learning curve. But, once you’ve done it a few times, it becomes exponentially easier. Practice makes perfect and, in the meantime, ugly falling apart rolls taste just as good as perfect ones. 

Once you have the hang of it, making sushi at home is no more difficult or time consuming than making any other relatively special weekend meal - like a lasagna or a chicken dinner. It’s not “quick and easy” but it’s doable and worth it - especially if, for whatever reason, you don’t have access to restaurant sushi. There are, however, ways to make the process easier:

Preparation is Key

To make good sushi there are a few techniques you need to do correctly, but none of them are particularly challenging, as long as you’re not aiming for perfection. The key is to have everything ready in advance, before you start to assemble the rolls. Have all your ingredients chopped and cooked, and the rice and vinegar mixture made in advance. Keep your workspace clean and organized, with everything you need laid out conveniently.

Opt not to make your own tempura flakes

The crunch from the tempura flakes is essential to these rolls, as it provides contrast with the creamier texture of the sweet potato and avocado and the soft texture of the rice. But, you don’t have to make it yourself. Ready made tempura flakes are available in some grocery stores, local Asian grocers, or to order online. 

If you can’t find tempura flakes, you still don’t need to fiddle with deep frying batter - use panko crumbs instead! To substitute panko crumbs for tempura flakes, mix ½ cup of panko with 2 tablespoons of neutral oil and ¼ teaspoon of salt. Spread the panko onto a small pan over medium heat and stir frequently until golden brown and toasted, then set aside until ready to use.

Use Seasoned Rice Vinegar

Buying pre-seasoned rice vinegar is another shortcut you can take, which allows you to skip the step of dissolving salt and sugar in rice vinegar. 

Prep some Components in Advance

• Sushi rice can be cooked a few hours in advance of when you want to make the rolls. Store it at room temperature (never the refrigerator) covered by a damp kitchen towel until ready to use. 
• The sweet potato can be roasted in advance and stored for up to 2-3 days in the refrigerator.
• The vinegar mixture, if you’re making it from scratch, can be prepared in advance and stored in the refrigerator. 
• You can even prepare the rolls a few hours in advance of serving. Simply roll the sushi and wrap tightly in plastic wrap. Keep them at room temperature for up to a few hours until you are ready to cut and serve. (Note, if you are making rolls with fish in them, don’t leave them at room temperature for longer than 2 hours before consuming.)

What to Serve with Sushi

Soy Sauce

Soy sauce is an essential accompaniment for sushi rolls. Serve it in small individual pinch bowls for each diner. The idea is to carefully dip the corner of each piece into the soy sauce before eating. Be careful not to soak your sushi in the soy sauce or drop them in, otherwise soy sauce will be all you will taste!

Wasabi

Store-bought wasabi powder can be found at a well-stocked grocery store, Asian market or ordered online and stored at room temperature for a long time. Simply combine the powder with water, according to the package directions, and serve alongside your sushi.

Pickled ginger 

Pickled ginger is an optional accompaniment to sushi and - while I have been known to drape my pickled ginger right over each piece of sushi and eat it all together - it’s really meant to be eaten as a palate cleanser between different types of sushi. 

You may be able to find pickled ginger in a well-stocked grocery store, a local Asian grocer, or order it online. You can also make pickled ginger yourself, although it is meant to be made with young ginger, which is less fibrous than the ginger that is most widely available. 

Sriracha mayo 

Sriracha mayo is another accompaniment that is often served alongside (or on top of) sushi. It’s better suited for sushi rolls that have more fresh and crunchy ingredients - like a California roll - than these sweet potato rolls which are already on the sweet and creamy side, but if sweet and creamy is your thing, go for it!