Steam the broccoli and cauliflower until tender-crisp. If using frozen vegetables, steam in the microwave for just under the recommended time on the package. Drain all water from vegetables and set them aside.
Melt butter in a nonstick skillet over medium-low heat.
Add heavy cream. Let it warm up in the butter for 1-2 minutes.
When the cream begins to bubble, add cream cheese and whisk continuously until melted.
Add cheddar cheese, ranch mix, and salt, and whisk until completely melted.
Add water to thin out the sauce.
Put broccoli and cauliflower into an 8×8-inch square baking dish. Pour cheese sauce over the top of the vegetables. Give a light toss to coat them evenly.
Mix crushed pork rinds with melted butter. Sprinkle over top of the casserole.
Bake for 20 minutes, until golden and bubbly. Let rest 5-10 minutes before serving.