Gather all the ingredients.
Pat dry salmon with a paper towel. Cut salmon into 1 inch thick slices and place into a ziplock bag.
In a small mixing bowl, combine Miso, Japanese Sake, Soy Sauce and Swerve/Monkfruit. Mix well, pour marinade into ziplock bag and seal. You will need to marinate between 24 - 36 hours in a fridge.
After marination, wash off excess marinade and pat salmon dry with paper towel.
Place salmon on a silicone baking mat or oiled sheet of aluminum foil. Transfer salmon into the oven and cook at 425F for 8 minutes.
Meanwhile, in a large Teflon fry pan, melt butter on high heat. Once the butter is melted, add cauliflower rice and cook for 3-5 minutes stirring frequently or until desired tenderness. Transfer to serving bowl and set aside (or in a food warmer).
Finely chop green onions and set aside.
Once salmon is done, top with green onions and serve along with cauliflower rice.