First make the pickle. Pack the radish sticks and cucumbers into a jar, along with the cilantro. Heat the vinegar, water, and pepper flakes to a boil on the stove or in the microwave. Pour the hot brine over the vegetables, the liquid should just cover them. Set aside.
Whisk the dressing ingredients together, taste to adjust any of them, and set aside.
Cook the rice according to package instructions. Toss it with the seaweed and some of the dressing to moisten and flavor it.
Divide the rice between two bowls. Place the tuna in each bowl. Lift the tuna out gently with a fork to keep the chunks intact and leaving most of the oil in the can.
Arrange the rest of the ingredients around the bowl and drizzle with the dressing. Top with garnishes, and serve.
View the recipe instructions at The View From the Great Island