In a large bowl, whisk together the mayo, sriracha, coconut aminos, and sesame oil until well combined. Set aside.
Next, using a very sharp knife, cut the tuna steak into small, ¼ inch cubes.
Add the diced tuna, green onion and salt into the large bowl with the mayo mixture. Gently toss until well combined.
Refrigerate for at least 30 minutes prior to serving to allow the flavors to meld and the tuna to chill.
Serve as desired with rice, thinly sliced radishes, some avocado, diced cucumber, nori strips, jalapenos, and microgreens.