Begin by bringing a large pot of salted water to a boil. Add your pasta and cook until al dente per package instructions.

While the pasta cooks, pat the steak dry, season with salt and pepper, and sear it in 1 tablespoon olive oil over medium-high heat for 1-2 minutes on each side. Remove the steak from the pan and cover it to keep warm.

In the same pan, add the remaining olive oil and butter. Once melted, sauté the onions for about 3-4 minutes until they become translucent. Then, add the minced garlic and cook for an additional 30 seconds until fragrant.

Pour in the beef broth, scraping up the browned bits from the pan. Reduce the broth by half, then stir in the heavy cream and Italian seasoning. Allow the sauce to simmer for 3-4 minutes until slightly thickened.

Stir in the Parmesan cheese, mixing until it has melted and is well combined.

Slice the rested steak against the grain into thin strips. Drain the pasta, reserving ½ cup of the pasta water. Add the pasta to the sauce, tossing to coat it well. If the sauce is too thick, gradually add the reserved pasta water to achieve your desired consistency.

Gently fold in the sliced steak along with any juices accumulated on the plate. Heat through for about 1 minute and taste to adjust seasoning if needed.

Plate the pasta hot, garnished with fresh parsley and additional Parmesan cheese.