Start by bringing a large pot of salted water to a rolling boil over high heat. Add your favorite pasta and cook according to package instructions until al dente—about 8 to 10 minutes. Reserve 1 cup of the starchy pasta water before draining.

In a large skillet, heat a drizzle of olive oil over medium-high heat. Season sliced beef with salt and pepper, add to the skillet in a single layer, and sear for 3-4 minutes until browned. Remove and set aside.

In the same skillet, reduce heat to medium and add butter. Once melted, add chopped onions and sauté until translucent, around 3-4 minutes. Stir in minced garlic and cook for an additional minute.

Pour in chicken broth to deglaze the skillet, scraping up any brown bits. Let simmer for about 2-3 minutes.

Lower the heat, then stir in heavy cream and Parmesan cheese. Allow to heat until thickened, about 3-5 minutes, stirring frequently.

Add cooked beef back into the skillet along with drained pasta. Toss gently until everything is coated with the sauce. If too thick, add reserved pasta water until desired consistency.

Plate the pasta and garnish with chopped parsley and additional Parmesan cheese. Serve immediately.