Bring a large pot of salted water to a boil over high heat. Add 1 pound of pasta and cook until al dente, about 8-10 minutes. Reserve ½ cup of pasta water before draining.

Season 1 pound of steak with salt and pepper. Heat a skillet over medium-high heat and add 2 tablespoons of olive oil. Sear the steak for about 3-4 minutes per side to medium-rare. Remove and let rest, then slice.

In the same skillet, reduce heat to medium, add 3 tablespoons of butter. Sauté 1 medium diced onion until translucent, about 3-4 minutes. Stir in 4 minced garlic cloves and cook for an additional minute.

Pour in ¾ cup of beef broth, deglaze the pan and simmer for about 2-3 minutes. Stir in 1 cup of heavy cream and 1 teaspoon of Italian seasoning until smooth. Gradually fold in ½ cup of Parmesan cheese.

Combine the drained pasta with the sauce, adding reserved pasta water to reach desired consistency. Gently mix in the sliced steak, allowing everything to heat through.

Transfer to serving plates and garnish with chopped parsley.