Preheat your oven to 400F. Prick each potato a few times with a fork, and place them on a baking sheet. Roast them for 35-45 minutes, or until they're fork-tender.
Allow the potatoes to cool enough for you to handle them. Cut them in half and scoop the flesh out. To mash the potatoes, two options: 1) Use a food processor to pulse the potatoes, along with the almond milk, miso, and pepper, till it's semi smooth (you're aiming for smashed potatoes more than silky smooth mashed potatoes). Or 2) use a potato masher to mash the sweet potato, miso, almond milk, and pepper up. I personally like to use my processor, but I've been told by foodie friends that this is sacrilege.
To prepare the kale salad, place the kale in a large mixing bowl. Add the oil, avocado, lemon, and salt. "Massage" the ingredients into the kale, using strong hands and taking your time, until the kale is creamy and wilted down.
To prepare the sushi, lay a sushi sheet in front of you, with the shorter side of the rectangle facing you. Spread about 1/3-1/2 cup of the sweet potato mash on the nori roll. You should start a few inches above the bottom of the sheet and end a few inches below the top of the sheet. Create a layer of kale salad on top of that, and then make a horizontal strip of kimchee in the center. Roll the nori sheet up, starting at the bottom and going all the way to the top. Make a strip of moisture along the top edge of the nori sheet, so that it seals up when you finish rolling. Cut each roll into about 5 pieces.
Repeat the process 4 more times. You'll probably have some leftover sweet potato and kale leftover, which you can enjoy on its own!
The rolls will last for two days in the fridge, but they're best if eaten quickly.