In a skillet, heat the avocado oil, then cook the ginger and garlic over medium heat until fragrant. Add in the cauliflower rice and cook for about 5 minutes until tender. Remove from heat and let cool.
Cut the tuna and salmon into bite sized cubes.
In a bowl, combine the coconut aminos, rice vinegar, lime juice and sesame oil. Toss in the fish and allow to sit for at least 5 minutes.
Spoon the rice into a bowl, then arrange the fish, cucumber, radishes, avocado and mango on top of the rice. Spoon any remaining sauce over the fish and other toppings.
Sprinkle the cilantro, sesame seeds and red pepper flakes (if using) over the top and enjoy!