Pat the sushi-grade ahi tuna dry with a paper towel and dice into 1/2-inch cubes.
In a medium glass bowl, whisk together the coconut aminos, rice vinegar, sesame oil, and freshly grated ginger.
Add the tuna cubes to the bowl, tossing gently to coat, and let marinate in the refrigerator for 10 minutes.
Steam or sauté the cauliflower rice until tender, then season with sea salt and black pepper.
Thinly slice the cucumber, radishes, and green onion, and pit and slice the avocado.
Divide the cauliflower rice into bowls and top with the marinated tuna and edamame.
Arrange the cucumber, radishes, and avocado slices on top for a vibrant presentation.
Garnish with sliced green onions and toasted sesame seeds before serving.