Spray 8×8 baking dish with nonstick cooking spray. Cut one cauliflower into chunks and boil until tender, drain well. Saute 1/4 cup diced onion in oil until softened, add 2 cloves diced garlic and 1/2 tsp dried thyme and cook for 2 more minutes, turn off heat. Place cauliflower and 4 oz softened cream cheese in a bowl and blend with a hand mixer (or use food processor). Add up to 2 tbsp cream if needed to blend mixture. To the mixture, add onion, salt and pepper to taste and 1/3 cup shredded cheese (I used mozzarella, but any white cheese you like will do). Spread mixture in baking dish and sprinkle another 1/3 cup cup shredded cheese on top. Bake at 400 for 20 minutes.