Place half the cauliflower florets in the blender or food processor. Use the pulse button to chop until finely chopped and resembles rice or couscous. Empty into a bowl and repeat with the remaining cauliflower.
Heat oil in a large non-stick skillet over medium heat. Add the onions and cook until translucent, about 4-5 minutes. Add the garlic and cook until fragrant, about 30 seconds.
Increase temperature to medium-high and add the cauliflower. Saute and stir for 5-7 minutes until desired tenderness (don't let it cook too long or it will get mushy). Season with the salt and pepper. Place in a serving dish and garnish with parsley.