Using a very sharp knife, cut fish into roughly 1-inch cubes and place in large bowl.
Add avocado, cucumber, and green onion to fish.
Place cauliflower into food processor and pulse just until processed into "rice" sized grains. Set-aside.
Whisk last eight ingredients in a separate bowl to combine. Pour into bowl of fish and vegetables.
Mix gently to coat fish and vegetables in sauce.
Refrigerate to chill and marinate for 20 minutes. Serve over raw cauliflower "rice."
Notes
As noted above, it is very important to follow guidelines on using raw fish, to purchase sushi-grade quality, and to work closely with your fishmonger to ensure safety.
Recipe by Autoimmune Wellness at https://autoimmunewellness.com/raw-citrus-poke-salad/