Step 1

Place oven rack on middle rack, preheat oven to 450 degrees, and coat 9×13-inch baking pan with nonstick cooking spray.

Step 2

Cook bags of cauliflower rice on stovetop over high heat, covered with a lid, until cooked through, about 5-7 minutes, stirring occasionally. Transfer to large mixing bowl and set aside.

Step 3

In same pan over medium heat, melt 2 tbsp (1 oz) butter. Add white onion and cook, uncovered, until onion is fragrant and slightly softened, about 2-3 minutes. Add minced garlic and cook for additional 30 seconds. Remove from heat and set aside.

Step 4

To mixing bowl of cauliflower rice, add remaining 2 tbsp (1 oz) butter, sour cream, shredded cheddar, green onions, onion powder, salt, and pepper. Using an electric mixer, mix together until well-combined. Add white onion and garlic and mix again.

Step 5

Transfer mixture to prepared baking dish and, using a rubber spatula, spread into even layer. Sprinkle grated Parmesan on top. Transfer pan to oven and bake until cheese topping is melted, about 8 minutes. Then, move oven rack to top rack and turn on oven broiler. Cook until cheese on top is lightly golden, about an additional 1-2 minutes, watching carefully to ensure it doesn’t burn.

Step 6

Remove pan from oven and allow to cool slightly before serving. Optionally, garnish with green onions.