Cook the fettuccine according to package instructions until al dente. Drain and set aside.
In a large skillet, heat the olive oil over medium-high heat. Season the sliced steak with Cajun seasoning, salt, and pepper.
Add the steak to the skillet and cook for about 3-4 minutes, or until browned and cooked to your liking. Remove the steak from the skillet and set aside.
In the same skillet, add the minced garlic and sauté for about 30 seconds until fragrant.
Pour in the heavy cream and bring to a simmer. Stir in the grated Parmesan cheese until melted and smooth.
Add the cooked fettuccine and the cooked steak back into the skillet. Toss everything together until well combined and heated through.
Serve immediately, garnished with chopped parsley.