Combine seasonings for shrimp from Creole seasoning - black pepper in a small bowl, setting aside 1 tablespoon Toss together shrimp with seasoning mix in a Ziploc bag until shrimp are evenly coated.
Heat large skillet over medium heat. Add chopped bacon and cook until browned. Remove bacon and set aside. Discard all but 1 tablespoon bacon fat. Return pan to heat. Add sliced mushrooms and cook 3 minutes, stirring frequently. Add bell peppers and cook 1 minute. Make a well in the center and add shrimp. Cook shrimp until firm and opaque, about 3-4 minutes. Add the bacon back to the pan and stir all together. Remove toppings from heat and set aside.
Heat stock in a saucepan over medium heat until simmering, but not boiling.
Heat a large skillet over medium heat. Add 1 tablespoon olive oil. When the oil is hot, add onion and garlic. Saute until onions are softened, about 4 minutes. Add pasta and toast until golden brown, about 5 minutes. Add stock, 1 cup at a time, stirring constantly until the stock has been almost all absorbed before adding more liquid. The pasta will take about 35 minutes total.
Add the shrimp mixture to the penne and stir to combine. Stir in grated parmesan and reserved 1 tablespoon seasoning mix. Garnish with parsley. Serve.