Combine garlic, grated ginger, mirin, soy sauce, lemon juice, toasted sesame seed oil, rice vinegar, and the white parts of the green onions together in a large mixing bowl. Slice the salmon into 1 inch cubes against the grain, and add to the mixing bowl with the poke sauce. Toss to combine and marinate for 15-45 minutes, no longer than 1 hour.
Meanwhile, cook the rice according to package instructions
Divide the cooked rice between bowls and top with marinated salmon, sliced cucumber, radishes, avocado, and mango.
