I soaked the Korean kelp I had found in the Korean market for 1 hour (the instructions said 40 minutes.) Then I rinsed it and soaked it for about 10 more minutes. Then I took the pieces out of the water and cut them to sushi piece sizes, and returned them to the water until I used them.
To assemble, I placed a pinch of parsnip/olive oil/apple cider vinegar mix on a piece of kelp. Then I placed a small glob of grated carrot, some snow pea sprouts (cut in half), and some grated onion. Then I rolled it all up and put it on a plate.
I found that longer sushi were hard to eat – we needed to cut them with a knife. Once they were bite-sized, they were easy to eat as finger food. My room-mate dipped hers in soy sauce.