Cook the fettuccine pasta according to package instructions until al dente. Drain and set aside.

In a large skillet, heat the olive oil over medium-high heat. Season the steak pieces with salt and black pepper, then add them to the skillet. Cook until browned, about 3-4 minutes. Remove the steak from the skillet and set aside.

In the same skillet, add the diced onion and cook until softened, about 3-4 minutes. Stir in the minced garlic and cook for an additional 1 minute until fragrant.

Pour in the heavy cream and beef broth, stirring to combine. Bring the mixture to a simmer and let it cook for 5 minutes until slightly thickened.

Add the cherry tomatoes and cooked steak back into the skillet. Cook for another 2-3 minutes until the tomatoes are warmed through.

Toss the cooked fettuccine with the sauce in the skillet until well coated. Mix in the grated Parmesan cheese until melted and combined.

Serve hot, garnished with chopped parsley.