Add oil to a large skillet and heat over MED HIGH heat until hot. Add beef, onion, and garlic and cook for 5-7 minutes, breaking up the meat as it cooks.
If lean beef was used, and there's not much grease in the skillet, you can just continue cooking to simmer that grease away. If there's a lot of grease, you'll want to drain it.
Add in Italian seasoning, salt, pepper, red pepper flakes, and flour, stirring well to combine. Cook, stirring often, for 2 minutes.
Add tomato sauce and stir. Add heavy cream, cream cheese and sour cream and stir well. Simmer a few minutes, stirring often, to really incorporate the cream cheese into the sauce.