In an 8x8 or 9x9-inch baking dish, add rice, spinach, onion, garlic, ½ cup parmesan, oregano, thyme, salt, pepper, water and soy sauce and stir to combine. Add mushrooms and press down into a compact layer. Cover tightly with foil and bake for 60 minutes or until the rice is cooked through (there will still be liquid at the bottom).