Cook the macaroni, in boiling salted water, according to the manufacture's directions. I undercooked my macaroni by 2 minutes so they soak up more sauce while they cook further, later in the recipe. Drain and set aside until needed.
In a double boiler, or if you have a fancy steamer, steam the cauliflower until soft and can be easily pierced by a knife, approx 7 minutes.
While the cauliflower is cooking, sauté the garlic and onion, with a good pinch of salt and pepper, until they are soft and slightly brown, approx 5-7 minutes. Set aside until needed.
Once the cauliflower is cooked, put it in a food processor, or blender, along with the onion, garlic, and ½ a cup of the milk. Process or blend all the ingredients together until the mixture is completely smooth and creamy.
Pour ¾ of the cauliflower mixture into a large pot, that's been heated over medium heat. Add your cheddar and gruyere cheese, and stir constantly until the cheese is completely melted. Now add your cooked macaroni, a cup or so at a time, and stir until everything is well combined. While stirring, the mixture will start to get "stringy" because of the melted cheese. Add your remaining ½ cup milk, a little at a time, until you reach the creaminess you desire. Of course add more if you feel the mixture needs it. Taste for salt and pepper, adding as much as you see fit.
At this point, if you like creamy mac and cheese, you can eat it as is! It will be delicious!
However, if you prefer baked mac and cheese, you can do a few extra steps!
Preheat the oven to 350 degrees
Pour the mixture into a greased 8x8 or 9x9 cake pan and sprinkle the top with smoked, or regular, paprika.
If you don't like bread crumbs on your mac and cheese, bake it without the bread crumbs for 20-30 minutes, or until the cheese starts bubbling.
If you DO like a bread crumb topping, do the following...
In a small skillet, melt 2 tablespoons of butters. Add the bread crumbs, stir and cook on medium heat, until the the bread crumbs are toasted, it should only take a few minutes.
Top the mac and cheese with the buttery, toasted bread crumbs.
Put the mac and cheese in the oven and bake for 20-30 minutes, or until the cheese starts bubbling.
Once the cheese mixture is bubbling, take it out of the oven, and let rest for 10 minutes.
Enjoy!