Cook the pasta per the package instructions in salted water until al dente. Drain well and set aside.
In a 12-inch cast iron skillet cook mushrooms, bell pepper and onion in a few drizzles of olive oil over medium high heat. Season with salt and black pepper to taste. Cook for around 2-3 minutes just until softened and beginning to brown. Add the garlic, cook for 1 minute.
To the skillet add ground beef and Italian sausage. Cook until no pink remains. Drain all excess fat from the pan.
To the skillet add the olives, cream cheese, pizza sauce, pepperoni and Italian herb seasoning. Stir until combined. Simmer for 5 minutes.
Next, add the cooked pasta, grated Parmesan and 1 cup of shredded cheese to the pan. Stir until the cheese has melted. Sprinkle the top with the remaining cheese.
Remove from the heat and let stand until the cheese has melted or place under the oven broiler to melt, then serve garnished with parsley.