Prepare your pasta according to the package instructions.
Sautee the red pepper and onion in butter over medium heat.
Add the shrimp and the cajun seasoning and sautee until shrimp are cooked through.
Add the diced tomatoes and cream to the peppers and onion mixture.
Add 1/2 cup of pasta water to your sauce and let simmer for several minutes. This will help your sauce to thicken!
Toss the sauce with the noodles, add the parmesan cheese and serve!