Preheat oven to 200C/180C fan-forced. Combine wasabi, ginger, garlic, mirin, sugar, sesame seeds and tamari in a small bowl. Squeeze soy beans from pods. Discard pods.
Place 1 piece of baking paper onto the centre of each piece of foil. Top each with a salmon fillet and drizzle with 1 tablespoon of tamari mixture. Fold edges of foil together to enclose filling. Place parcels on a baking tray. Bake for 20 minutes, for medium, or until cooked to your liking.
Meanwhile, cook rice blend following absorption method on packet, adding soy beans and snow peas in the last 5 minutes of cooking. Remove from heat. Stir in oil, 3/4 of the onion and remaining tamari mixture. Top with spinach. Set aside, covered, for 5 minutes. Stir to combine.
Divide rice mixture between plates. Carefully open parcels and transfer salmon and sauce to plates. Serve topped with remaining onion.