In a skillet, cook bacon until cooked through. Remove and allow to cool. Then chop.
In a large bowl place cauliflower with water. Cover and steam in microwave for 5-8 minutes. Drain.
Place cauliflower in food processor and blend until consistency of mashed potatoes.
Blend in butter, garlic powder, sour cream and chives to the mashed cauliflower. Season with salt and pepper to taste.
Spread mashed cauliflower mixture evenly onto the bottom of a greased casserole dish. Top with the chopped bacon and grated cheese.
Bake in a 375° oven for 15 minutes, until cheese is melted. Serve warm.
Chives can be omitted or replaced with green onions.Any grated cheese can be used in place of Monterey and cheddar. Cream cheese is a great substitute for the sour cream and helps thicken the mashed cauliflower.