Rinse and pat dry the cauliflower. Remove all the leaves. Slice from the top to the bottom stem, into 1/4" thick slices. The cauliflower should basically fall apart. The idea is to create thin bite size pieces for the most part. Layer half the slices into the bottom of your baking dish. I used a round 10" dish. Season the slices generously with salt, pepper and red pepper flakes. Add the cooked sausage, if desired. Layer the rest of the dish with cauliflower. Set aside.
Preheat oven to 350 degrees. In a saucepan over medium heat, melt the butter. Add the starch and whisk together. Add the milk and continue whisking until smooth and heated through. Add half of the cheddar cheese and stir to combine. Continue stirring until the cheese is melted and smooth again. Add half the mozzarella slices and stir again. Repeat. Stir the sauce until the final cheese is melted and smooth. Add salt and pepper and then pour over the cauliflower. Bake for 20 minutes, or until cheese is golden browned and bubbling. Enjoy!
Cheesy Cauliflower Mac ‘n Cheese https://barefeetinthekitchen.com/cheesy-cauliflower-mac-n-cheese/