Prepare the penne pasta by cooking it in boiling water until just tender but still firm to bite. Drain it well, setting aside a cup of the pasta cooking water.
Heat olive oil in a large frying pan over medium heat, then cook the chopped onions and minced garlic until soft and aromatic, about 5 minutes.
Add the ground beef into the pan, breaking it into pieces as it cooks. Continue until the meat turns brown and cooked through, around 7 minutes. Season with salt, pepper, and Italian seasoning.
Turn the heat down low and pour in the heavy cream. Slowly mix in some of the reserved pasta water until the sauce reaches the texture you want. Stir in the Parmesan cheese until it melts smoothly.
Toss the cooked penne into the skillet with the creamy beef sauce, mixing gently to combine everything well.
Dish out the pasta hot, and if you like, top with extra Parmesan or chopped fresh parsley before serving.
