Bring a large pot of salted water to a boil. Cook the penne pasta according to package instructions until al dente, about 8-10 minutes. Drain, saving 1 cup of pasta water.

In a large skillet, heat olive oil over medium heat. Sauté diced onion and minced garlic for about 5 minutes until softened.

Add lean ground beef to the skillet and cook for about 7 minutes, stirring occasionally until browned. Season with salt, pepper, and Italian seasoning.

Pour in heavy cream, stirring to combine. Gradually add reserved pasta water until desired consistency is reached. Stir in Parmesan cheese until melted.

Add drained penne pasta to the skillet. Toss until every piece is coated in the creamy sauce.

Serve in bowls with extra grated Parmesan and chopped parsley as garnishes.