Cut cauliflower into florets. Place in a large bowl with 1-inch water. Microwave cauliflower on HIGH for 14 minutes or until cauliflower is tender. Drain water from cauliflower. Set aside.
Heat butter in a large skillet over medium-high heat. Add flour; stir with a whisk and cook for 1 minute. Stir in heavy whipping cream, Cheddar, mozzarella, Parmesan, salt, pepper, and thyme. Cook until cheeses melt and mixture is combined.
Add cauliflower to cheese mixture; stir well to coat.
Transfer mixture to an 8- x 8-inch baking dish. Sprinkle top with pork rinds.
Bake at 350° for 20 minutes.
Notes
TIP: If you want the most mac n' cheese texture possible, chop the cooked cauliflower into elbow macaroni-sized pieces before adding it to the cheese. This dish serves really well with Keto Stir Fry, Keto Chicken Thigh Recipes, and Keto Chili.