In a food processor, add cauliflower florets in 3-4 batches and process until “rice” forms. The key to proper coarse rice texture is not to overcrowd the bowl of food processor. Transfer to a medium bowl and set aside.
Preheat large non-stick skillet on medium – high heat and add mushrooms. Cook until golden brown or about 5 minutes, stirring occasionally. Transfer to a medium bowl and set aside.
Return skillet to medium heat and swirl oil to coat. Add onion and garlic, sauté until translucent or about 3 minutes, stirring occasionally.
Add cooked mushrooms, cauliflower “rice”, broth, salt and pepper. Stir, cover and cook for 4 minutes.
Turn off heat, add Parmesan and mozzarella cheese and parsley; stir until cheese is melted. Serve warm with chicken of choice (I like almond crusted chicken).