Cook rice and quinoa together in a pot, just covered with water and with 1 teaspoon miso mixed in. Bring to a boil and then lower to very low heat; cook, covered, for 20-25 minutes until all liquid is absorbed and grains are tender.
Preheat oven to 200C. Place salmon on a roasting dish lined with baking paper. Mix 2 teaspoons of miso and mirin and spread over the salmon. Roast salmon for 10 minutes, or until just cooked through. When cool enough to handle, gently flake apart (leave skin behind).
While salmon is cooking, prepare the rest of the bowl. Prepare vegetables for pickle and place in a bowl. Mix vinegar, salt and sugar together and mix, then pour over carrots, cucumber and radish. Set aside. (You can keep this in a ziplock bag in the fridge for a couple of weeks).
place rice and quinoa in the bottom, then add spinach, slaw, salmon and capsicum. Top with pickled veggies, mayo, kimchi, seeds and other garnish.
This bowl can be assembled in a plastic container and kept in the fridge until ready to eat.