Add sliced sausage to a saute pan set over medium-high heat and cook until nicely seared on both sides. When the sausage is almost done cooking add the shrimp and cook for approximately four minutes, or until the shrimp is cooked through and sausage is well seared.
Remove the sauteed shrimp and sausage from the skillet, setting aside in a large bowl, and drizzle bottom of pan with olive oil along with onion and peppers. Set to medium heat and cook until the onion and peppers are tender, then add the garlic cloves and cook for an additional two minutes.
Remove the onion, pepper, and garlic and set it aside with the sausage and shrimp.
Add chicken broth, heavy cream, cajun seasonings, crushed tomatoes, and a sprig of thyme to the saute pan. Bring the sauce to a simmer and scrape the bottom of the skillet to incorporate any cooked on browned bits into the sauce. Let simmer for 10 minutes.
While preparing the creamy sauce, add pasta noodles to a large pot of salted boiling water and cook according to the package instructions until al dente.
After the sauce has thickened, remove from heat and stir in the Parmesan cheese. Then add set aside sausage, shrimp, peppers, onion, and garlic along with cooked fettuccini noodles. Toss everything to combine and serve immediately.
Notes
If you crave spicy food, drizzle in some cayenne pepper hot sauce, or crushed red pepper flakes.