Preheat your oven to 400 degrees F. Poke the potatoes with a fork, and place them directly on the rack in the oven. Place a piece of foil on the rack below if you are worried about them oozing. Bake for 40-45 minutes or until tender. Remove from heat and set aside to cool for a couple of minutes, and then place the potatoes in the fridge to chill completely, about 1 hour.
Meanwhile, prepare your mushroom mixture. Heat the oil in a large saute pan, over medium heat. Add the mushrooms and cook until brown and tender, about 8 minutes. Add the onions and a dash of salt and pepper. Cook until the onions are translucent and have just begun to caramelize. Sprinkle in the Italian seasoning and stir. Add the chicken broth and increase the heat until it comes to a boil and then reduce the heat. Simmer until the chicken broth has cooked out, about 10-15 minutes. Remove from heat and set aside to cool slightly.
Taking your cooled potatoes, cut the tops off lengthwise. Scoop the flesh (out of the tops and the bottoms) out of the potatoes into a large bowl, leaving 1/4 inch of border left around each potato. Place the potatoes on a large baking sheet that has been lined with foil. Spray with a non-stick canola oil spray and season with salt and black pepper.
In the large bowl with the flesh from the potato, add the mushroom and onion mixture, gruyere cheese, sour cream and butter. Mash all of the ingredients together until they come together and the mixture is mostly smooth.
Mound the mixture evenly into each potato. Bake the potatoes at 400 degrees F for 20-25 minutes or until the tops just begin to brown slightly.
Remove from heat and let cool for just a minute and then top with crumbled bacon and parsley. Enjoy!