In a large sauce pot, add butter over medium heat.
Season shrimp with 1 tablespoon Cajun seasoning, sauté in butter for 1 to 2 minutes per side and set aside in a bowl.
Raise the heat to medium high heat and add sausage, onion, peppers and 1tablespook Cajun seasoning to shrimp pot ; cook until vegetables start to brown, 6 - 8 minutes.
Add garlic and cherry tomatoes to the pot and continue cooking until garlic starts to brown, 3 - 4 minutes.
Add in cream and bring mixture to a boil, reduce cream, stirring constantly. When cream holds a line on the back of the spoon, turn off the heat and add in gruyere cheese, taste for seasoning.
Bring a pot of salted water up to a boil and cook fettuccine until al dente, drain water, reserving ½ cup pasta water, and add pasta, parsley, shrimp and a splash of pasta water to cream sauce, stirring to bring everything together.
