Step 1: Cook the Pasta
Bring a large pot of generously salted water to a rolling boil. Add the rigatoni and cook according to package directions until al dente. Reserve ½ cup of pasta water before draining. Drain the pasta and set aside.

Step 2: Season and Sear the Steak Tips
Pat the steak tips dry with paper towels and toss them thoroughly in the Cajun seasoning, ensuring each piece is coated. Heat the olive oil in a large cast-iron skillet over medium-high heat. Add the steak tips in a single layer, working in batches to avoid overcrowding. Sear for 2-3 minutes per side for medium-rare, or to your desired doneness. In the last minute, add the 2 tablespoons of butter and baste the steak tips. Remove the steak and set aside.

Step 3: Start the Cheese Sauce Base
In the same skillet (do not clean it), reduce heat to medium. Melt the 4 tablespoons of butter. Add the minced garlic and cook for 1 minute until fragrant. Sprinkle the flour over the butter and garlic to create a roux. Whisk continuously and cook for 1-2 minutes until the roux is light golden.

Step 4: Create the Creamy Foundation
Gradually pour in the warm milk and heavy cream while whisking constantly to prevent lumps. Continue to cook, whisking frequently, until the sauce thickens enough to coat the back of a spoon, about 5-7 minutes.

Step 5: Build the Cheesy Parmesan Sauce
Reduce the heat to low. Gradually whisk in the grated Parmesan cheese, one handful at a time, waiting for each addition to melt before adding the next. Stir in the Italian seasoning and smoked paprika. Season with salt and white pepper to taste. Remember, the Parmesan is salty, so taste first.

Step 6: Combine the Pasta, Sauce, and Steak
Add the drained rigatoni to the cheese sauce, tossing to coat thoroughly. If the sauce is too thick, add the reserved pasta water a few tablespoons at a time until it reaches a creamy, cohesive consistency. Gently fold in the seared Cajun steak tips and any accumulated juices from the plate.

Step 7: Garnish and Serve Immediately
Garnish with fresh chopped parsley and an extra sprinkle of Parmesan cheese. Serve immediately while the steak is still tender and the sauce is luxuriously hot and creamy