Rub Cajun spice into the surface of the meat. Cover with plastic wrap and let sit while you prepare the sauce and pasta. (The rub will actually begin to "cure" the meat.)
For the sauce, melt butter in a large saucepan which will be large enough to accommodate the pound of cooked pasta, and saute onion until it becomes translucent. Mix in the flour to make a roux. Gradually add chicken broth and allow thickening. Remove from heat and whisk in Parmesan. Immediately cover surface of sauce with a sheet of plastic wrap and set aside briefly.
Bring a pot of water to boil for the pasta.
Heat olive oil over medium-high heat in a skillet. Cook the sun-dried tomatoes for a few minutes, then with a slotted spoon transfer them to the cheese sauce and whisk in. Cover the pot of sauce and set aside. Reserve the skillet and all the bits in it for the meat.
Boil the pasta until al dente and drain. Add the cooked pasta to the saute pan containing the sauce and fold to coat pasta. Season with salt and pepper, as needed. Keep covered in a warm place while you cook the steaks.
Over medium high heat, sear the steaks, about 3 minutes per side and cook to your liking. Slice steaks into bite sized pieces and serve over pasta.