Make Dashi broth according to Dashi recipe. Or you can use an instant Dashi.
Chop green onion finely. Peel the Daikon and cut into quarters lengthwise and slice thinly. Cut salmon into bite size pieces.
Bring dashi to a boil, and cook the Daikon and salmon in dashi for 5 minutes covered at medium low heat. Turn off the heat and dissolve miso.
Serve in a bowl and top with chopped green onion.