Make the dashi ahead of time. Have that shit ready
While your washed rice is cooking, start on the salmon. Cook to doneness and let it rest a minute. Flake it.
Cook your mushrooms in the same pan.
Start letting your broth simmer a bit. You don't want it boiling, just let it cook down a touch.
When the rice is done, put it in a bowl and top with the salmon and whatever other veg you're using.
Pour the broth over. Top with furikake if you want. Eat with a soup spoon.