Cook the pasta according to package directions. Drain and set aside. You can toss the cooked pasta with a little oil to keep it from sticking.
In a large skillet melt 2 tablespoons of the butter over medium-low heat. Once the butter has melted turn the heat up to medium-high. Add the steak pieces and cook for 30-45 seconds. Flip the steak pieces and cook for an additional 1-2 minutes, until the steak is browned on both sides and done to your liking. Remove from the heat and keep warm.
Melt the remaining butter over medium heat. Add the garlic and parsley and sauté for about 1 minute, be careful not the burn the garlic. Add the flour and salt and sauté for another 1-2 minutes. Add the milk, slowly while whisking to incorporate it with the flour/butter mixture. Simmer for 10-15 minutes until the sauce is bubbling and has thickened slightly. Add the cheddar cheese and stir until melted.
Add the cheese sauce and the cooked steak to the pasta and mix well.