1. Drain the liquid from the beets and dice them into large chunks. Slice the tuna into equal size chunks as the beets.
2. Grate the garlic and ginger.
3. Add everything into a medium sized bowl with the rest of the ingredients.
4. Use a round-shaped cutter to plate the tartare. Top with sliced radish and more (Could also use scallions, chives, shaved cucumbers, or, year-round, pea shoots.)