Creating Beef and Garlic Butter Pasta is a straightforward process. Just follow these easy steps:

1. Cook the Pasta: In a large pot of salted boiling water, cook the fettuccine according to package instructions until al dente. Reserve ½ cup of pasta water, then drain.
2. Prepare the Beef: Season the sliced beef with salt and pepper.
3. Sear the Beef: In a large skillet over medium-high heat, melt 2 tablespoons of butter. Add the seasoned beef and cook until browned, about 3-4 minutes. Remove from the skillet and set aside.
4. Make Garlic Butter: In the same skillet, add the remaining 2 tablespoons of butter. Once melted, add the minced garlic and red pepper flakes (if using). Sauté for about 1 minute until fragrant.
5. Combine Ingredients: Return the beef to the skillet. Add the drained pasta and toss to combine. If the pasta seems dry, gradually add reserved pasta water until you reach the desired consistency.
6. Add Cheese: Stir in the grated Parmesan cheese until well incorporated.
7. Garnish: Remove from heat and mix in the chopped parsley.
8. Serve: Transfer to serving plates and garnish with additional Parmesan, if desired. Serve with lemon wedges for a fresh touch.