Rinse rice under cold water using a fine-mesh sieve.
Take a pot and pour in fresh cold water and rice vinegar. Add rinsed rice and salt.
Bring it to boil. Once boiling, turn the heat low. Simmer until the water disappears, then remove from heat and cover with a lid. It should stay covered for 5 minutes. Now, you have cooked sushi rice.
Roast sweet potato and beetroot
Peel and cut sweet potatoes into fries approx. ½-inch thick. Do the same for beetroot, but cut it thinner approx. ¼-inch. Place them in a single layer on separate sheet pans or on baking trays or on parchment paper (the beetroot will color the sweet potatoes purple if they are too close during baking).
Make a quick marinade with soy sauce (or tamari), maple syrup, sesame oil, and vegetable oil. Brush the sweet potato fries, turn and brush the other side as well. Brush the beetroot fries with oil only and sprinkle it with some salt and pepper.
Preheat the oven for 400 Fahrenheit (220 degrees Celsius) and roast the sweet potato and beetroot fries until soft and tender.
Roll you sushi
Take a bamboo mat and place a dry nori sheet on it.
Take 2-3 spoonfuls of cooked sushi rice and using your fingers spread it evenly and thinly over the nori sheets. Make your fingers wet to avoid the rice sticking to them too much.
Make 3 lines horizontally around ⅓ of the nori sheet. One line should be sweet potato fries, one beetroot fries and one avocado sliced also as fries.
Take the bamboo mat and roll the sushi as tight as you can manage. (You can watch our video how we do it, or check out the step-by-step photo collage above the recipe card.)
Once it is tightly rolled, cut it into 1-inch wide sushi rolls.
Repeat with all 4 nori sheets. You should have approx. 25-30 sushi rolls.
How to roll exactly?
We made a video how we do it, but above the recipe card there is a step-by-step photo collage to show you each step.
Fold the bottom of the nori sheets with the help of the bamboo mat in the height of the filling.
Gently roll it further until the bottom side hits the other side of the sushi.
Apply a bit of pressure through the bamboo mat to squeeze the filling a bit together.
Roll back the bamboo mat and tuck in any overflowing filling.
Now, wrap it up with the bamboo mat again and roll it all the way to the end of the nori sheet.
Apply a bit of pressure again and voila your are done! Here is your first sushi roll.