Pre-heat oven to 375. Heat avocado oil over medium heat in nonstick skillet. Add onions and mushrooms and saute until soft. Add pinch of salt and pepper and stir. Remove from heat and allow to cool for a few minutes. Riced the cauliflower in food processor or use pre-riced cauliflower. In a large bowl, mix together both meats, pork rinds, cauliflower, garlic, parsley, and sauteed mushrooms and onions. Mix well. Layer the bottom of a casserole dish with the tomato sauce and chicken stock. Place peppers in the dish, skin side down. Fill the peppers with the stuffing, divided evenly and top with the parm cheese. Wrap the dish tightly with heavy foil and place in oven for 45 minutes. Carefully remove the foil and increase oven temp to broil. Let peppers broil 3-5 minutes until brown. Remove from oven and serve with low carb veg such as wilted spinach.