Steam Cauliflower “Rice” according to the packaging directions.
Sauté onions and mushrooms in a hot pan over medium-high heat until mixture begins to brown, about 4-5 minutes. Remove and place in a large mixing bowl along with the steamed Cauliflower “Rice” and add all remaining ingredients. Mix well, then using your hands moistened with water, shape into 12 large or 24 small balls.
In a frying pan, preheat a thin layer of oil over medium-high heat and fry the balls on all sides, about 2-3 minutes per side or until golden brown.
Serve with marinara sauce.
Note: Makes 12 to 24 “meatballs,” depending on yield size.