1/8-1/4cupof water (as needed to make a thick batter)
1Tablespoonof neutral oil
Combine rice and water in a medium pot and bring to a boil. Lower to a simmer, cover and let cook undisturbed for 15-20 minutes depending on rice type, until fluffy and sticky. Transfer to a bowl and set aside to cool a bit.
While rice is cooking prepare your crispy sweet onion filling, by combining chickpea flour/cornmeal in a bowl with just enough water to form a thick batter. Toss in onion slices and mix with your hands to coat. Place onion slices on lightly oiled baking sheet and bake at 450 degrees for 15-20 minutes or roughly until rice is done. Flip once if necessary, they should come out golden brown, crispy and sweet inside.
While onions and rice are cooking, saute mushroom slices in a skillet in a tablespoon of sesame oil until browning, about 5-7 minutes.
Cut all raw veggies, and add to cutting board or large plate along with mushrooms and onions. Add rice vinegar, agave, and salt to bowl of rice and toss well with a wooden spoon to coat.
Get sushi set up ready; you will need nori sheets, rice bowl, all filling ingredients laid out in front of you, a sharp knife, a small bowl of water, and a small cutting board or surface to roll sushi on.
Take a sheet of nori and cover the 3/4 closest to you with a thin layer of rice. Thinner is better, it just barely needs to cover the seaweed. Place a line of vegetables in the center starting with carrots/cucumbers on the bottom, then adding a bit of mushrooms, onions, avocado and cabbage last. Put WAY less than you think you should of each ingredient (less is usually more with sushi). It will also be much easier to roll.
Fold side of seaweed closest to you over top of the veggies and gently push down and pull back towards you, so as to grab and tighten the veggies in the roll as best you can. Continue rolling away from you until you get to the bare end of the seaweed. Dip one finger in bowl of water and run it along the bare seaweed edge. Continue to roll sushi (the water will make the edge stick). Admire your work and cut into 1-1 1/2' pieces and transfer to a serving plate to serve with favorite soy sauce/tamari/coconut aminos and wasabi. Enjoy!