Boil the pasta according to package instructions. While the pasta is boiling, add the onion and pepper to a medium saucepan and saute.
Add the shrimp to the veggie mixture, and toss with the cajun seasoning. Saute until shrimp are pink and cooked through.
Make the sauce by adding the diced tomatoes and cream to the saucepan. Cook for about 5-10 minutes, until the sauce thickens to your desired consistency.
Remove the shrimp sauce from heat and add the cooked pasta noodles and parmesan cheese. Toss to combine.
Garnish the pasta with fresh parsley and additional parsley and serve.
Reserve 1 cup of pasta water from the noodles. Adding the water to the sauce, a bit at a time, will help thicken your sauce.