I found this recipe on a Facebook page called RecipeGirl. I tried to pinch it from the site but it didn't work for some reason so I had to enter it manually. If you want to check the page out for yourself the link is thelondoner.me/...e-rib-tickler.html.
Pasta: Cook the pasta according to package directions. Drain and set aside (toss with oil to prevent sticking).
Steak: Melt 2 tablespoons butter in a large, sturdy skillet over medium low heat. Continue to heat the butter until it's barely browned (this just gives it more flavor). Turn the heat up to medium high and add the steak pieces - do not stir or shake for 30-45 seconds. Flip the steak pieces and cook for another minute or two, until the steak is done to your liking. Remove from heat and keep warm
Sauce: Melt the remaining butter over medium heat. Add the garlic and parsley - saute for about a minute, being careful not to burn or brown the garlic. Add the flour and salt - saute for another minute or two. Add the milk slowly, whisking to incorporate with the flour/butter mixture. Simmer for 10-15 minutes until the sauce is bubbling and has thickened slightly. Add the cheese and stir until melted.
Assembly: Stir the pasta together with the cheese sauce and add the steak. Stir in extra water or broth if the consistency needs a little thinning out. Season with more salt and pepper, or if you're really awesome, drizzle truffle oil over the whole thing.