Cook pasta according to package instructions. Drain and set aside.
Season steak with salt, pepper, and 1 tablespoon Cajun seasoning. Cook to desired doneness in a skillet. Let rest, then slice.
In a sauté pan, melt butter and cook shrimp with remaining Cajun seasoning until pink.
Add minced garlic to the pan and sauté for 30 seconds.
Pour in heavy cream and bring to a simmer. Stir in Parmesan cheese until smooth.
Toss cooked pasta with the Alfredo sauce.
Serve pasta topped with sliced steak and Cajun shrimp. Garnish with fresh parsley.