Preheat the oven to 350 degrees and spray a 3-quart or 8x8 baking dish with cooking spray.
Boil a large pot of water and add your prepared green beans. Cook for 3-5 minutes until they are crisp tender. Drain them from the water and set aside.
Add butter to a medium saucepan over medium/high heat. When butter is melted, add onions. Sauté the onions for 3 minutes then add the mushrooms and garlic.
Cook the mushrooms for about 3 minutes. Pour in chicken stock, making sure to scrape off any browned bits from the bottom of the pan. Turn heat down to medium and stir in cream cheese, dijon mustard, parmesan cheese, salt and pepper until cream cheese is melted through.
Toss in green beans until they are coated and then turn off the heat.
Spread the green bean mixture into the prepared baking dish. Prepare the topping in a small bowl by combining the ground pork rinds, parmesan cheese, and butter. Sprinkle topping over the green beans.
Bake for 20-30 minutes until the casserole is bubbling and topping is browned. If you like an extra crispy topping, you can place the casserole under the broiler for 2 minutes once it is done baking.
This recipe makes approximately 4 cups of green beans and each serving is about 1/2 cup.