Place your sheet of nori down on a cutting board, shiny side down. Add on about 3/4 of a cup of the cooled brown rice on the middle part of the sheet. (See photos for reference).
Add on a layer of kale in the middle of the brown rice, then add on 6-7 pieces of the sweet potato.
Dip your finger in water, and wet the top edge of the nori sheet. This will help the nori stick together when you roll it.
Roll your sushi roll as tightly as you can. You can use a sushi mat if you'd like, but it can also be done without one!
When your sushi is rolled, let it rest for about 5-10 minutes so that the nori can stick together.
Repeat the above steps until you are out of your ingredients. Note that you may have some rice left over.
Now it's time to cut the sushi into slices. First, get a tall glass and fill it with water. Quickly dunk the sharpest knife you have in the water, then slice the sushi. (You can slice it with a dry knife, but in my experience I've found that the water greatly helps!)
When all the sushi is cut, garnish with sesame seeds, sriracha, and microgreens (if desired).
Enjoy!