Cook the sushi rice according to the packet instructions. While the rice cooks, mix the rice vinegar, sugar, and salt in a small dish until dissolved. Once the rice is cooked, pour the vinegar mixture over the hot rice and stir to coat the grains. Toast the sesame seeds in a small pan, then stir them through the rice. Set aside to cool slightly.
Remove the skin from the salmon fillets and chop them into chunks. Dice the spring onions. For the teriyaki marinade, mix the maple syrup, sesame oil, tamari, garlic granules, and mirin in a small dish.
Once the rice has cooled to a warm temperature, divide it between two bowls, covering two-thirds of each base. Fill the remaining third with edamame beans and sliced avocado.
Heat the teriyaki marinade in a small frying pan over high heat until it bubbles. Reduce to a simmer and stir until the sauce thickens. Add the salmon chunks and increase the heat, stirring to fully coat the salmon with the glaze. Sprinkle the spring onions over the top and cook until the salmon is glazed and cooked through.
Place the glazed salmon and spring onions over the sushi bowls. Serve with extra tamari soy sauce if desired.