Preheat oven to 375. Spray a small casserole dish with non-stick spray. Wash cauliflower, and cut into segments small enough to place in food processor. Pulse until cauliflower reaches a rice-like texture.
Place cauliflower in microwave safe bowl and microwave for 8 minutes. (Do NOT cover or add water).
Remove cauliflower from microwave and add the cauliflower back to the food processor, adding the rest of the ingredients, (except for the toppings). Pulse until mixture reaches the consistency of mashed potatoes.
Add half of the chives (or green onions), 1/4 cup cheddar cheese, half the bacon, and stir until well combined. Scoop cauliflower mixture into casserole dish. Sprinkle remaining cheese over top.
Cover with foil and bake for 25 minutes. Remove foil, and bake for an additional 5-10 minutes or until cheese is melted, and cauliflower is heated through. Remove from the oven, and add additional chives (or green onions) and bacon on top. Serve warm!