Season steak on both sides with a steak seasoning blend or salt and black pepper.
Heat 1 tablespoon of the butter in a skillet on medium-high heat. Once hot, add the steak and cook on both sides 2-3 minutes or to preferred doneness. Transfer steaks to a plate and set aside.
Add the remaining butter to the skillet. Once melted, add the bell pepper, onion, mushrooms and garlic. Cook 3-5 minutes or until the vegetables are tender. Transfer to a bowl and set aside.
Turn the skillet to high heat, and add beef broth and Worcestershire sauce. Once the mixture comes to a boil, add the spaghetti. Stir frequently and cook until the pasta is al dente.
Fold the reserved vegetables into the pasta.
Add both cheeses to the top of the pasta. Allow it to set for 1 minutes, then stir the melted cheese into the mixture until well combined. Turn off the heat.
Slice steak against the grain and place on top of the pasta.