Preheat the oven to 350. Carefully clean and prepare the box of mushrooms - using a damp paper towel, brush off any visible dirt. Gently remove the stems and set them aside. Once the caps are clean, rub them well inside and out with the truffle oil (olive oil if needed). Salt and pepper to preference (very important to add the salt and pepper on this step. Set caps aside.Using the mushroom stems, remove the tough ends and chop the stems very small. Heat 2 tbs olive oil in a skillet over medium heat, Add the onions, sausage and chopped mushroom stems to the skillet. Cook until sausage is cooked through and onions are not giving off any moisture. Add the garlic and dried thyme and cook for another minute.

Remove the mixture from the heat and add in the cream cheese, parmesan cheese, black pepper, salt and cayenne pepper. Mix well. Using a small spoon or scoop, fill each mushroom cap generously with the cheese filling. Place the mushroom caps in a baking dish, pour the chicken stock gently into the bottom of the dish - being careful not to splash any onto the tops of the mushrooms and fill to a depth of ⅛ inch. Sprinkle the tops of the mushrooms with the bread crumbs and the fresh cracked black pepper.

Place into the oven on the center rack and bake for 20-25 minutes until the tops start to brown slightly