1. Bring a large pot of salted water to a boil and cook the pasta according to the package directions until al dente. Drain and set aside.
2. Bring a medium pot of salted water to a boil, add the cauliflower and cook for 5-7 minutes, or until soft. Drain. Place the cauliflower in a blender and puree.
3. In a medium pan over medium heat, place the pasta, the cauliflower puree, the cheeses and the milk. Stir gently to combine and continue stirring until the cheese is melted.
4. Season with salt and pepper. Sprinkle the chopped parsley over the mac and cheese and serve immediately.