Prepare the Shrimp:
Toss the shrimp with salt, pepper, Cajun seasoning, and oregano until well coated.

Cook the Shrimp:
Heat a large skillet over medium-high heat and drizzle the bottom with olive oil. Add the shrimp and cook for 2 minutes on one side, then flip and cook for another 1-2 minutes until cooked through. Remove the shrimp to a plate and set aside.

Brown the Sausage:
In the same skillet, drizzle with a bit more olive oil, and add the sliced sausage. Cook until nicely browned and caramelized, about 4-5 minutes. Remove the sausage and set aside with the shrimp.

Cook the Pasta:
While preparing the sauce, cook the fettuccine in a large pot of salted boiling water according to the package instructions until al dente. Drain and set aside.

Sauté the Vegetables:
Lower the skillet heat to medium, add a bit more olive oil, and sauté the onion, red bell pepper, Cajun seasoning, brown sugar, and a pinch of salt. Cook until the vegetables have softened, about 4-5 minutes, stirring occasionally.

Add Garlic and Liquids:
Stir in the garlic and cook until fragrant, about 30 seconds. Add the crushed tomatoes, chicken broth, and heavy cream, stirring to scrape up any browned bits from the bottom of the skillet. Bring the mixture to a simmer.

Make the Sauce:
Once simmering, add the grated Parmesan and stir until it’s fully blended into the sauce.

Combine and Heat:
Add the cooked fettuccine and browned sausage back into the skillet, stirring to combine with the sauce. Heat everything through, about 2-3 minutes. Taste and adjust seasoning with salt and pepper, if needed.

Add Shrimp and Serve:
Finally, add the cooked shrimp back to the skillet and stir to combine. Serve the pasta topped with chopped parsley.