Prepare the Steak : Pat the steaks dry with a paper towel and season generously with Cajun or blackened seasoning on both sides. Heat a large skillet over medium-high heat and melt the butter. Sear the steaks for 3–5 minutes per side for medium-rare, adjusting for preferred doneness. Remove the steaks, cover with foil, and let rest while preparing the pasta and sauce.

Cook the Pasta : Bring a large pot of salted water to a boil. Cook the fettuccine according to the package instructions until al dente. Drain and set aside, reserving ½ cup of pasta water.

Make the Alfredo Sauce : In the same skillet used for the steaks, heat olive oil over medium heat. Add garlic and sun-dried tomatoes, sautéing until fragrant, about 1–2 minutes. Add the butter and melt completely. Stir in heavy cream and bring to a simmer. Gradually whisk in Parmesan and Gorgonzola cheeses until melted and smooth. Stir in diced tomatoes, black pepper, Italian seasoning, and kosher salt. Adjust the thickness with reserved pasta water if needed.

Combine and Serve : Add the cooked fettuccine to the sauce, tossing to coat evenly. Slice the steaks into strips and serve on top of the pasta. Garnish with fresh parsley and additional Parmesan if desired.