To make the ponzu dipping sauce, mix all the ingredients together. To make the sushi, use a bamboo rolling mat, and cover with 1 sheet of nori. Spread some quinoa on the bottom two thirds of the nori. Use your hands to make a 1cm thick covering. Add a layer of spinach, then the avocado, the carrot and the peppers 1cm up from the bottom of the quinoa. Drizzle with the teryaki sauce if using. Tightly roll the sushi from the base of the mat, to make a long thin roll. Repeat with the remaining ingredients. Chill. When serving, use a wet knife to slice the sushi into 4cm lengths, serve with the ponzu or soy sauce, wasabi and ginger.