Prep the oven and dish: Preheat the oven to 375°F (190°C). Grease a 9x13-inch baking dish with butter or cooking spray.
Soften the base: In a large bowl, beat the softened cream cheese until smooth.
Add sour cream, mayonnaise, and heavy cream. Mix until creamy and well combined.
Season the sauce: Stir in garlic, onion powder, smoked paprika, salt, pepper, Parmesan, and half of the cheddar. Fold in the parsley.
Add the chicken and veggies: Fold in the shredded chicken and any optional low-carb veggies.
If using spinach, wilt and squeeze it dry first; if using broccoli or cauliflower, steam lightly and pat dry.
Assemble the casserole: Spread the mixture evenly into the prepared baking dish. Sprinkle the remaining cheddar over the top.
Make the topping: In a small bowl, combine crushed pork rinds, almond flour, melted butter, a pinch of salt, and the extra cheese. Toss to coat evenly.
Add the crunch: Sprinkle the topping across the casserole in an even layer for maximum crispness.
Bake: Place the dish on the center rack and bake for 25–30 minutes, until hot and bubbly with a golden-brown top.
If the top browns too quickly, tent loosely with foil.
Rest and serve: Let it rest for 10 minutes to set. Garnish with more parsley and serve warm.