Clean and cut stems from brussel sprouts, removing outer leaves as needed. Shred the sprouts. I used a grater drum, but you could use a food processor, mandoline, or whatever tool you have on hand.
Put sprouts into a baking dish.
Add red pepper flakes, and liberally salt and pepper your sprouts. Mix the shredded cheddar into shredded sprouts.
Put softened cream cheese, butter, and heavy cream into a bowl and microwave for a few seconds at a time until you can easily mix them together in a thick sauce. (If you don't use a microwave, you could do this over a low heat on the stove.)
Add the cream and cream cheese sauce to your shredded sprouts and mix well.
Add olive oil to parmesan and melt in the microwave, a few seconds at a time (or on your stove).
Dot the parmesan on top of your sprout mixture and spread it around a bit.
Sprinkle crushed pork rinds on top.
Bake until brown on top and bubbly, about 20 minutes.
If you like your au gratin creamier, up the heavy cream to 1/2 cup. I might do that next time myself. And I'm thinking this would be good with a little lemon juice added to offset the flavor, or maybe varied with different types of cheese or spices added in. Let me know what you try!