Cook the pasta according to package instructions. Drain and set aside.
Season steak with 1 tablespoon Cajun seasoning. Heat 1 tablespoon olive oil in a skillet over medium-high heat, cook steak for 3-4 minutes per side until browned. Remove and set aside.
Season shrimp with remaining Cajun seasoning. Add 1 tablespoon olive oil to the skillet and cook shrimp for 2-3 minutes per side until pink. Remove and set aside.
In the same skillet, add 1 tablespoon olive oil and sauté garlic for 1 minute. Add red bell pepper and cook for 5 minutes until tender.
Reduce heat to medium. Add heavy cream and stir in Parmesan cheese until smooth. Season with salt, pepper, and red pepper flakes if desired.
Add pasta to the sauce and toss to coat. Return steak and shrimp to the skillet and mix until heated through.
Garnish with parsley and serve warm. Enjoy!