In a medium sized bowl, combine soy sauce, sesame oil, rice wine vinegar, ginger, garlic, and green onions. Stir well to combine. Add salmon and marinate for about 30 minutes in the refrigerator.
With a vegetable peeler, peel thin, long ribbons of cucumber; thinly slice, or mandolin, the radishes; quarter the avocado, and cut into thin slices; peel carrots and then cut into 1-inch long, thin matchsticks.
Serve the salmon on top of brown rice and top with sesame seeds.
Then place the cucumber, radish, avocado, and carrots in the bowl with the salmon poke.