Boil a large pot of salted water. Cook the fettuccine until al dente, following package instructions. Drain and set aside, reserving some pasta water.

Heat a large skillet over medium-high heat, adding 2 tablespoons of butter.

Season the steak with salt, pepper, and a sprinkle of Cajun seasoning. Sear until browned, about 3-4 minutes per side. Remove from the skillet and set aside.

In the same skillet, add another tablespoon of butter and toss in the shrimp. Cook for 2-3 minutes until pink and opaque.

Season with additional Cajun seasoning and garlic, cooking for another minute until fragrant.

Reduce the heat to medium. Pour in the heavy cream, stirring well.

Add the Parmesan cheese and remaining Cajun seasoning, mixing until the sauce is creamy and smooth. If it's too thick, add a splash of reserved pasta water.

Toss the cooked pasta, seared steak, and shrimp into the Alfredo sauce, mixing until everything is well coated.

Garnish with fresh parsley and extra Parmesan cheese if desired. Serve and enjoy!